Occam

Sound pressure below about 20 Hz sits under the threshold of conscious hearing, yet the body still registers it. At certain frequencies it sets up sympathetic vibration in the chest, the inner ear, and notably the eyeballs (around 18-19 Hz), which smears peripheral vision into grey "movement". The combination of unease, a watched feeling, a half-seen shape at the edge of sight and sometimes nausea is the most reproducible "haunting" in the literature, ever since Vic Tandy traced his own lab ghost to a 19 Hz extractor fan.

You'll need: Infrasound-capable or data-logging sound-level meter; a phone spectrum app showing the 1-30 Hz band as a rough first pass.

The tell: The dread or visual smear is strongest in fixed spots and weakens when the mechanical source stops.

Ductwork is a building-wide speaking tube. Voices from a TV two rooms away, footsteps on the floor above or a conversation in the basement couple into the metal and reappear, oddly disembodied, at a vent on the far side of the house. Registers and dampers also tick, pop and boom as the system pressurises and the metal expands.

The tell: The sound only occurs while the HVAC runs, or arrives specifically at vents and registers.

When a valve or appliance shuts off quickly, the moving column of water slams to a stop and the shock travels the pipework as a bang or a run of knocks (water hammer). Trapped air and the thermal expansion of hot-water lines add groans, ticks and "footsteps in the wall".

The tell: Knocks line up with water being used or shut off somewhere in the plumbing.

Every material in a building expands when warmed and contracts when cooled, each at a different rate. As the structure heats through the day and sheds that heat after sunset, timber joints, metal flashing, ductwork and masonry creak, crack and knock against one another. Activity famously clusters at the two daily temperature transitions, which is also when people are most primed to notice it.

You'll need: Temperature data-logger or a min/max thermometer; a notebook to timestamp each sound.

The tell: Knocks recur at the same structural spots and cluster around heating and cooling transitions.

Wind forced across a gap, a chimney mouth or the eaves behaves like breath across a bottle, producing moans, whistles and low resonant tones (Helmholtz resonance). The same pressure differences drive drafts through the building and can hold or swing a door.

The tell: The moaning rises and falls with the wind and stops when the gap is sealed.

Floors, joists and frames flex under load, whether from wind pressure on the building, someone moving on another floor, or the slow relaxation of timber. That flex transmits as creaks and "footsteps" that seem to come from an empty room directly above or beside the listener.

The tell: The footsteps match someone moving elsewhere in the structure, or track wind load.

Refrigerator and freezer compressors, water heaters, recirculating pumps and fluorescent ballasts all run on cycles, switching on and off with a hum, click or low drone that seems to come from nowhere once you have stopped consciously hearing the appliance.

The tell: The drone stops the moment the appliance is powered down.

A room's dimensions reinforce certain sound frequencies and cancel others, creating loud antinodes and silent nodes at fixed points. A steady tone can therefore seem to hang in mid-air, vanish when you step sideways, or "follow" a witness who moves between zones.

The tell: The sound's loudness depends on exactly where you stand, in a fixed repeatable pattern.

On still nights, and especially under a temperature inversion, sound refracts back toward the ground and carries for miles with little loss. Bar music, a train, a dog, a highway or a fairground can arrive sounding close, directionless and "inside" the building.

The tell: The sound is audible outdoors as something distant, and conditions favour long-range carry.

Tinnitus generates tones, hiss or hum inside the listener's own auditory system. In a quiet, dark vigil, exactly the conditions investigators create, it becomes far more noticeable and is easily externalised as a faint sound "in the room".

The tell: Only one person hears it and it travels with them from room to room.

Unshielded audio gear, long cable runs and cheap recorders act as accidental radio receivers. Baby monitors, taxi and CB radios, two-way handsets and even strong broadcast signals bleed snippets of speech and music into recordings and PA systems, surfacing later as "voices".

You'll need: A second recorder of a different type; an RF or spectrum scanner if available.

The tell: The voices change or disappear when devices are removed or you change recorders or location.

Live mains wiring, junction boxes, outlets and especially old knob-and-tube or ungrounded runs radiate a steady mains-frequency field. A general EMF meter reads this as a constant "presence" along a wall, and sustained exposure is the kind of field some people report as unease.

You'll need: EMF meter, ideally one showing frequency or AC/DC; access to the breaker panel.

The tell: The field is steady, follows the wiring, and drops when you cut that circuit's breaker.

Breaker panels, sub-panels, meter banks and the utility transformer on the pole or pad outside throw a large field that passes straight through an adjacent wall. A bed or chair backing onto that wall sits in a strong field with no visible cause inside the room.

You'll need: EMF meter.

The tell: The field peaks against the wall shared with a panel or an outside transformer.

Fluorescent fittings and dimmer switches emit EMF, an audible ballast hum and a subtle flicker all at once, a triple cue that gets variously logged as a meter spike, a phantom hum and "the lights reacting".

The tell: EMF, hum and flicker all share a single switch.

Solar activity raises the planetary geomagnetic index (Kp) and can disturb sensitive meters and, by some accounts, susceptible people. It is a minor contributor but worth a thirty-second check on an otherwise "active" night.

The tell: Instrument oddities coincide with an elevated Kp or a flagged geomagnetic storm.

Cold air enters through gaps around windows, doors, floorboards, electrical outlets and unused chimneys, and pours downward off cold glass. Felt on the skin it reads as a "cold touch" or a presence passing; pooled in one spot it reads as a discrete cold spot; channelled, it can nudge a balanced door.

You'll need: Incense stick or a tissue on a stick, or a thermal-imaging camera; a thermometer.

The tell: The cold has a direction and a source, and sealing the gap removes it.

Wherever warm and cool surfaces sit near each other, air circulates in a loop. That moving air reads as a "cold spot that drifts" or a chill that comes and goes as the convection cell turns over.

You'll need: Thermal camera or smoke source; a thermometer.

The tell: The cold moves along a predictable convection loop between warm and cool surfaces.

Cold air is denser and sinks, pooling at floor level, on stairs and in basements, while warm air stratifies near the ceiling. Step into the pool and you hit a sudden chill at shin or chest height with no source.

You'll need: Thermometer, ideally on a pole for a vertical profile.

The tell: A stable floor-to-ceiling temperature gradient explains the chill.

Stone, tile, marble and any damp surface feel dramatically colder than wood or carpet at the same air temperature, because they pull heat from your hand faster, and damp ones cool by evaporation. Witnesses report a "cold presence" when the air is actually uniform.

You'll need: Infrared surface thermometer and an air thermometer.

The tell: Air temperature is even and only the surface is cold to the touch.

Thermal cameras are routinely misread. Glass, mirrors, glossy paint and polished metal reflect heat like a mirror, so your own warm reflection can appear as a "figure", and emissivity differences make ordinary objects show false cold or hot shapes. Many thermal apparitions are simply the operator reflected back.

You'll need: Thermal-imaging camera plus a spot IR thermometer to cross-check.

The tell: The figure is a reflection that moves with the operator or vanishes from another angle.

The visual system is a face- and body-detector tuned to fire on the slightest cue, so it imposes faces and figures onto random texture, shadow, foliage, wallpaper and photographic noise. It is the most common single cause of apparitions in stills and dim rooms, and once someone names what the shape "is", everyone else sees it too.

The tell: The figure only resolves once you know to look for it, and naive viewers do not agree on it.

Peripheral vision is low-resolution, colour-poor and motion-biased, excellent for detecting that something moved but useless for telling you what. It readily manufactures a dark figure or shadow that is there until you turn to look, at which point sharp central vision finds nothing.

The tell: It is always caught out of the corner of the eye and never survives a direct look.

A car turning outside throws its headlight beam through a window and sweeps it across the wall and ceiling as a moving band of light, easily a "figure crossing the room" or a travelling glow, especially through blinds or trees that break it up.

The tell: The light sweeps in time with passing vehicles and stops when the window is covered.

Glazing, mirrors, picture glass, TV screens and even still water act as partial mirrors, throwing back the image of a person, a candle or a passing light so it appears to stand or float within the scene.

The tell: The figure is a reflection that moves with its real-world source.

Pressure on the eye, drifting bits of vitreous (floaters) and the afterimages of bright light all create lights and shapes that originate inside the eye itself. They drift with the gaze, persist with the eyes shut, and have no external source.

The tell: It travels with the eye and is invisible to anyone else.

Migraine and some related conditions produce a visual aura, shimmering zig-zag arcs, expanding blind spots, sparkles or geometric light, with or without a subsequent headache. It can be vivid and frightening and is purely neurological.

The tell: A spreading, shimmering geometric disturbance over 20 to 30 minutes, often with headache.

In near-darkness the brain has too little information and fills the gaps from expectation, turning a coat rack, a curtain, stacked boxes or a dressing gown on a door into a standing figure. Fear and a haunted-place narrative steer what it fills in.

You'll need: A camera and a torch.

The tell: Lighting the scene reveals a mundane object exactly where the figure stood.

People with significant sight loss commonly experience vivid, detailed visual hallucinations, figures, patterns, scenes, while otherwise completely lucid and aware the images are not real. It is benign, under-recognised, and worth knowing about.

The tell: Vivid visions in a lucid person who has serious vision loss.

As you wake from REM, the body's dream-paralysis can briefly persist while the mind is alert. The result is the classic bedroom visitor: you are awake, unable to move or speak, with crushing chest pressure, a terrifying sense of a presence, and often a hallucinated dark figure, footsteps or breathing. It is common, harmless and culturally universal, the Old Hag, the incubus, the alien at the bedside.

The tell: Paralysis plus dread plus a figure, occurring right at the boundary of sleep.

In the drowsy moments drifting into or out of sleep, the brain throws up vivid images, voices (often hearing your own name), flashes of light, a falling sensation or a sense of presence: hypnagogic and hypnopompic hallucinations. They feel real because you are half awake.

The tell: Brief dreamlike images or a called name in the moments around sleep.

A false awakening is a dream of waking up in your own room, convincing, mundane, and easily incorporating the haunting. You seem to get up, see a figure, then truly wake later, certain it was real.

The tell: A "real" awakening that contained dream-logic gaps and was followed by truly waking.

Seeing, hearing, feeling or smelling a recently deceased loved one is extremely common and entirely normal in grief; a majority of bereaved people report it at some point. It is not pathology and not, by itself, evidence of a haunting. It is the mind processing loss.

The tell: The experiences are of a specific recently-lost person and fit the grief context.

An orb is a mote of dust, a pollen grain, a water droplet, a snowflake or a tiny insect floating within a few centimetres of the lens, lit by an on-camera flash and thrown wildly out of focus into a soft, often ringed disc. The effect exploded with compact digital cameras whose flash sits right beside the lens. They are not spirits.

You'll need: The camera that took the shot; a dusty or damp spot to reproduce.

The tell: They only appear with flash and reproduce instantly when you stir dust near the lens.

A bright light in or just outside the frame bounces between the glass elements inside the lens and reappears as streaks, polygons, rings or a misty "energy", often coloured, often geometric, often mirrored across the centre of the image from the light source.

The tell: A geometric or coloured artefact positioned opposite a bright light source.

A wrist strap, a strand of hair, a coat fibre or the edge of a finger dangling near the lens and lit by flash becomes a glowing "vortex", a white streak or a translucent "rod" across the shot.

The tell: A flash-lit streak that matches a strap, hair or finger near the lens.

In cold air, breath, vape or cigarette smoke drifts in front of the lens and the flash lights it into curling "mist" or "ectoplasm". Backscatter, flash bouncing off rain, snow or dust, does the same. It billows, drifts and dissipates like the vapour it is.

The tell: Cold conditions plus drifting mist that dissipates frame to frame.

Long exposures and camera shake smear point lights into trails and ribbons, while aggressive JPEG and video compression invents blocky artefacts, halos and "figures" in shadow and noise, especially after a file has been copied, zoomed or re-saved.

The tell: The anomaly lives in a compressed or zoomed copy and disappears in the untouched original.

Night-vision and full-spectrum rigs flood the scene with infrared the eye cannot see. That IR reflects off particulate, retroreflective surfaces and animal eyes, and produces glows, shapes and bright points only the camera registers, easily mistaken for something present in the dark.

The tell: It appears only through the IR or night-vision device and tracks the illuminator.

The brain is desperate to hear speech and will pull words out of random noise, radio hiss, HVAC rumble or muffled distant sound, especially once someone provides a suggested transcript, after which it is almost impossible to un-hear. This is the core mechanism behind most EVPs.

The tell: Naive listeners disagree on the words until they are told what to hear.

Recorders are indiscriminate. A whispered aside, a stomach gurgle, a swallow, clothing rustle, a chair creak, a phone vibrating in a pocket, wind, or someone in the next room all get captured and resurface in review as a disembodied "voice" or "response".

The tell: The voice lines up with an un-logged but mundane human sound during recording.

Old buildings rarely have level floors. A slope of even a degree or two sends balls, bottles and round objects rolling "on their own", and lets a balanced door drift open or shut. It looks intentional and is pure gravity.

You'll need: A spirit level or a marble; a phone level app.

The tell: Objects always travel downhill along a measurable slope.

A door is a large, balanced sail. Opening an exterior door, the HVAC cycling, a gust of wind or even closing another door changes the air pressure in the building and pushes a balanced internal door open or shut, the house "breathing".

The tell: The door moves whenever the building's air pressure changes.

Worn hinges, an out-of-plumb frame and a latch that does not quite catch let a door creep open under its own weight with no push at all. People "close" it without latching, and minutes later it has swung wide.

You'll need: A spirit level.

The tell: The door only opens itself when it was not actually latched, and it leans that way.

Heavy lorries, buses, trains, the subway and nearby construction send low-frequency vibration through the ground and structure. Over time it walks objects toward the edges of shelves until they fall, and rattles glass, doors and fixtures in time with the passing source.

You'll need: A vibration-sensing app or sensor; local transport timetables.

The tell: Rattles and movement sync with heavy traffic, trains or works nearby.

Swings in humidity swell and shrink timber, slacken old adhesive and fatigue picture wire, so doors stick then suddenly free, and pictures and shelves fall, often dramatically and often at night when temperature and humidity shift most.

You'll need: A hygrometer.

The tell: Failures coincide with humidity swings and show fatigued, not snapped-by-force, fixings.

Fresh paint, new carpet and underlay, adhesives, solvents, cleaning products and some old materials off-gas volatile organic compounds that smell odd and can cause headaches, lightheadedness and unease in an unventilated space.

The tell: Symptoms and odd smells follow recent renovation or new materials and improve with ventilation.

The investigation method itself manufactures altered states. Long overnight vigils, sleep deprivation, dehydration and low blood sugar all degrade perception and, pushed far enough, produce mild hallucination, misperception and emotional volatility, exactly in the small hours when "activity" peaks.

The tell: Experiences cluster late in long, tiring sessions among the most fatigued people.

Prescription side-effects, including some common ones, alcohol, cannabis and other substances alter perception, mood and suggestibility. This applies to witnesses and investigators alike and needs a tactful, non-judgemental check.

The tell: The experience coincides with substances or medications known to affect perception.

Mice and rats living in walls, ceilings and under floors scratch, gnaw, scurry and squeak, often at a set time each night, and can push small objects, drag nesting material and leave droppings and a smell. It is one of the commonest causes of "something moving in the walls" and phantom footsteps in the ceiling.

You'll need: A torch; a wildlife or trail camera; tracking dust or a simple bait check.

The tell: Scratching or scurrying at a regular nightly time, with physical signs like droppings and gnawing.

Birds and bats in a chimney, soffit or loft, and larger animals such as squirrels, raccoons and possums in attics and crawlspaces, produce thumps, scrabbling, drags, flapping and fleeting movement at dawn and dusk, plus the odd animal that gets into living space and is glimpsed as a "dark shape".

You'll need: A torch; a trail camera; safe ladder or loft access.

The tell: Thumps and scrabbling concentrated at dawn and dusk, with nesting evidence and entry points.

The deathwatch beetle taps its head against timber to attract a mate, a slow rhythmic ticking from within old structural wood, which is exactly where the folklore of the death-watch omen comes from. Crickets, cicadas and other insects add chirps and tones mistaken for electronic or vocal sounds.

The tell: A slow, regular tick from inside old timber, seasonal and temperature-dependent.

Owls, the barn owl's shriek especially, foxes screaming in the mating season, and other night animals produce sounds uncannily like a woman screaming, a baby crying or a person calling out, a very common source of "disembodied screams" heard outdoors or through walls.

The tell: An outdoor scream or cry that matches a barn owl or a fox in season.

A dog or cat staring at "nothing", growling at a corner or bolting is routinely read as the animal sensing a spirit. But animals hear into the ultrasonic and down toward the infrasonic, and smell traces we cannot, so they are almost always reacting to a real, mundane stimulus we simply cannot perceive.

The tell: The animal consistently orients to a spot where a real, if imperceptible-to-us, stimulus is found.

A single fine strand of spider silk, or a tiny insect, drifting against the face, neck or arm produces an unmistakable light "touch" or tickle, frequently reported as being stroked by an unseen hand, especially around head height in old, low-traffic rooms.

The tell: A faint brush at head height where stray silk or insects are found.

A mouse, rat, bird or squirrel that has died inside a wall, duct or void produces a powerful "smell of death" that builds over days and then fades, frequently reported as a sudden, sourceless stench of decay or "something evil".

The tell: A decay smell that peaks then fades over days, strongest at one spot in the structure.

Expectation shapes perception. Controlled studies have shown that simply telling people a place is haunted, or that activity is increasing, significantly raises the number and intensity of experiences they report, even in identical, inert locations. A tour guide's preamble, a reputation, or another investigator's gasp primes everyone who follows.

The tell: Reported activity rises sharply once people are told to expect it.

We count the hits and quietly forget the misses. An EMF meter that twitches once in an hour, a knock that happens to follow a question, a name the spirit box "got right", all get logged and remembered, while the hours of nothing and the hundreds of wrong words are discarded, manufacturing a pattern out of noise.

The tell: The evidence is a handful of hits pulled from a sea of unrecorded misses.

Tiny, unconscious muscle movements, invisible to the person making them, drive Ouija planchettes, dowsing rods, pendulums and table-tipping. The participants honestly feel the object moving by itself because they are not aware they are moving it. It is the same mechanism behind facilitated communication and the Chevreul pendulum.

The tell: Performance falls apart the moment the operator cannot see what they are spelling.

Adrenaline primes the brain for threat. In a dark, scary setting the perceptual system biases hard toward detecting danger, so a shadow becomes a figure, a creak becomes footsteps and a draft becomes a touch, and racing-heart arousal gets reinterpreted as a supernatural charge in the air.

The tell: The experience happened at a moment of high fear and does not survive a calm re-look.

Experiences spread socially. One person's gasp, a "did you hear that?", or a report seeds the same perception in a group, so several people independently feel a presence or hear a sound when really they cued each other.

The tell: The shared experience traces back to one person's cue rippling through the group.

Memory is reconstructive, not a recording. Accounts gain vividness and detail with each retelling, timelines compress, and people genuinely misremember who moved an object or what was said. The story that reaches you is often more dramatic and more coherent than the original event.

The tell: The account grows more detailed and dramatic in later tellings than in the first.

There are real incentives to manufacture or exaggerate a haunting: ticket sales, a property's notoriety and value, media and book deals, attention, or simply not wanting to admit a mistake. Motivated owners, guides and witnesses may stage events, withhold mundane explanations, or unconsciously perform.

The tell: Activity depends on a specific motivated person and stops under independent controls.

Not all staging is by the owner. A child or teenager seeking attention or amusement, a prankster, a flatmate with a grudge, people knock on walls, move objects and create "phenomena" for reasons of their own, sometimes playful and occasionally malicious.

The tell: Phenomena cease when the suspected individuals are watched, filmed or excluded.

In terraces, semis, flats and tightly-packed buildings, the neighbours come through the party wall and shared structure: muffled voices, footsteps, music, plumbing, cooking smells and light spill, all arriving oddly and read as coming from within.

The tell: The activity comes through a shared wall or floor and tracks a neighbour's routine.

The team is the biggest source of false data. Your own footsteps carry to another room, a whisper is caught on a recorder, body heat shows on thermal, your phone spikes the EMF meter, your movement trips a sensor, all logged later as anomalies because no one tracked who was where.

The tell: The anomaly matches a team member's movement, voice, heat or device.

General-purpose EMF meters were built to find wiring faults and check appliances, not to detect spirits. They respond to mains wiring, motors, chargers, phones, microwaves and each other, and cheap ones drift and spike on their own. Without a baseline, every ordinary field looks anomalous.

The tell: The responses trace back to wiring, devices, or the absence of any baseline.

The K-II meter is popular precisely because it lights up readily, but it is unshielded and responds to cell signals, two-way radios, cordless phones and broadcast RF. Its dramatic "answers to questions" track radio traffic and the timing of your own phones, not intelligent responses.

The tell: The K-II stops answering once phones and radios are removed.

A spirit or ghost box sweeps rapidly through live radio frequencies, so by design it spits out fragments of real broadcasts, words, music, voices. Your brain stitches these random scraps into answers via audio pareidolia. The meaningfulness is entirely in the listener.

The tell: Responses are sweep-radio fragments and vanish under RF shielding.

An Ovilus and similar devices read environmental sensors, convert the values to entries in a built-in dictionary, and speak the word. Any apparent relevance is coincidence amplified by apophenia and by the operator steering interpretation. There is no evidence the inputs carry meaning.

The tell: The device produces words from its own dictionary regardless of any presence.

A REM-pod radiates its own field and alarms when any conductive mass, a hand, a body, a phone, even a draft of charged air, enters that field. Investigators leaning in, walking past, or a nearby electronic device set it off routinely.

The tell: The alarm coincides with someone or something conductive entering its field.

"It drained the batteries" is one of the most-cited paranormal signs and one of the most mundane. Cold saps battery voltage fast, cheap and partly-used cells collapse under load, and devices behave erratically as the voltage sags, all ordinary battery chemistry.

You'll need: Fresh, tested batteries; a simple battery tester; a charge log.

The tell: Drain tracks cold temperatures and cheap or used cells.

Without a baseline sweep and calibrated, understood equipment, you have no idea what "normal" is for the space, so ordinary ambient readings and the gear's own quirks get logged as anomalies. Most activity is the absence of a control, not the presence of something.

The tell: The anomaly is within the range a proper baseline would have shown as normal.

Ghost-radar, EMF and word apps on a phone have no access to real field-sensing hardware for this purpose; they are entertainment products driven by random-number generators and the phone's ordinary sensors. Their output is designed to look spooky, not to measure anything.

The tell: The readings come from a phone app rather than calibrated hardware.

Passive motion sensors and laser grids are tripped by insects, dust, drafts, curtains, temperature changes and small animals. A bug crossing the beam at night reads as "something moved through the room".

The tell: The trip has no accompanying sound or mass, consistent with a bug or a draft.

Venus is the reigning champion of misidentified lights, brilliant, low, and made to twinkle and appear to "move", "pulse" and change colour by atmospheric scintillation. Bright planets and stars near the horizon do the same. The great majority of hovering-light and many UAP reports are this.

You'll need: A planetarium or sky-chart app; a compass.

The tell: The object matches a bright planet or star's position and barely moves over minutes.

Aircraft, including distant ones with unusual light patterns, helicopters, the ISS, Starlink satellite trains and drones all produce moving lights, sometimes silent, sometimes oddly coloured or in formation, that read as UAP, especially when distance and darkness remove the usual cues.

You'll need: A flight-tracker app; a satellite-pass predictor.

The tell: The light's path and timing match a tracked aircraft or satellite pass.

A bright meteor or fireball is a brief, fast, sometimes fragmenting streak that can flare dramatically and even appear to descend nearby. They explain striking one-off sky lights, especially during known meteor showers.

The tell: A brief, fast, one-off streak coinciding with meteor activity.

Ground mist, fog, drizzle and low cloud scatter light into glows and halos, soften shapes into figures, and wreck photographs with reflected flash. They also make distant ordinary lights loom and shift eerily.

The tell: The effect only appears in mist, fog or rain and not in clear conditions.

A temperature inversion bends light, lifting, stretching and doubling distant lights, ships, coastlines and headlights into hovering, shimmering apparitions, the Fata Morgana. It explains floating lights and "ghost ships" on the horizon.

The tell: A distant known light source is being lifted and distorted by an inversion.

Outdoors, wetland gas and bioluminescent fungi (foxfire, on damp rotting wood) create faint, pale, drifting glows, the traditional will-o'-the-wisp and corpse candles of marshes and old woods.

The tell: Faint pale glows tied to wetland or rotting wood, outdoors.

A debated hypothesis holds that stress in the Earth's crust near faults can generate light phenomena and electromagnetic effects, and possibly perceptual ones, which might cluster some apparition and UAP reports geographically. It is speculative but cheap to check off.

The tell: Lights or effects cluster near active faults around times of seismic stress.

Electrical arcing, sparking and some motors generate ozone, giving a sharp, clean, metallic or electric smell that is often reported alongside the EMF spikes from the very same faulty wiring or device.

The tell: A sharp metallic or electric smell coinciding with EMF spikes near faulty wiring.

Smells travel and linger. HVAC and drafts carry perfume, pipe or cigar smoke, flowers, baking or cooking between rooms, and old upholstery, curtains and timber hold scents for decades, releasing them with warmth or humidity, the textbook "grandmother's perfume" or phantom pipe smoke.

The tell: The scent tracks airflow or comes off old fabric or wood when warmed.

Dry air plus synthetic carpets and clothing build static charge that discharges as a touch, a tingle, a prickle or hair standing up, read as being touched or as "energy" in the room.

The tell: Brief tingles or sparks in dry conditions with synthetic materials.

A limb "falling asleep" (paresthesia from sustained pressure on a nerve), benign muscle twitches and the hypnic jerks that hit as you drift off all produce sensations of being touched, tugged or jolted by something external.

The tell: The touch matches a numb limb, a muscle twitch, or the moment of falling asleep.

The body's own fear response, piloerection (hair standing up), chills running down the back, a prickling scalp, is generated from within and then interpreted as an external "energy", a cold presence or being touched, completing the loop between expecting a ghost and feeling one.

The tell: The energy or touch is the body's chill-and-prickle fear response during a frightening moment.