False positives and innocent causes
Most of what Findy flags is ordinary. That is expected — each method measures a physical property that thousands of harmless objects also have. This page tells you what those objects are and how to rule them out before you worry about anything.
A tool sensitive enough to notice a hidden device will also notice a screw head, a smart speaker and your neighbour's printer. An app that only ever showed you real findings would be hiding its own uncertainty. Findy shows the evidence so you can dismiss things quickly.
Camera and lens checks
The lens-glint tools look for a small bright point that shifts as you move. Plenty of things do that.
- Screws, screw heads and polished fittings — the single most common cause. Bright, round, and they move with your viewing angle exactly as a lens does.
- Glass and glossy plastic — picture frames, clock faces, appliance panels, varnished wood and mirrors.
- Metal trim — handles, hinges, brackets, sockets and light fittings.
- Status LEDs — small, bright and often recessed behind a lens-like cover.
How to rule them out
- Change your position by 10 cm and look again. A flat reflective surface changes brightness smoothly; a lens tends to flash sharply within a narrow angle.
- Move the light source rather than only the phone.
- Look at the object directly, without the app. Most of these identify themselves instantly as a screw or a hinge.
- Ask whether the object plausibly houses electronics at all. A door hinge does not.
Infrared viewing
The infrared mode shows sources that emit light your eyes cannot see. Many everyday devices do.
- Remote controls — press a button while viewing and the emitter glows brightly. That is a remote, not a camera.
- Standby and indicator LEDs on televisions, set-top boxes, air conditioning units and routers.
- Infrared sensors in motion detectors, automatic lights, thermostats and some alarm equipment.
- Some LED lighting, heating elements, and sunlight or reflections of it.
Infrared viewing also misses things. Many cameras have no infrared illumination at all, and iPhone infrared-cut filtering varies by model and camera. Seeing nothing is not a clear room.
The network scanner
Findy browses Bonjour services and probes a set of ports that IP cameras and recorders commonly use. So does a lot of ordinary consumer equipment.
| Device | Why it is flagged |
|---|---|
| Smart television | Handles video, advertises Bonjour services, often serves a web or control port. |
| Streaming stick or set-top box | Publishes media services; some expose an HTTP control interface. |
| Network printer | Advertises over Bonjour and serves an admin page on port 80 or 443. |
| Smart speaker | Constant service advertisements and open control ports. |
| Thermostat or smart home hub | Web interface plus service discovery on the local network. |
| Router or access point | Serves its own management interface on a common web port. |
| Baby monitor or doorbell you own | Genuinely a camera — and genuinely yours. |
Why does a television or printer look suspicious?
Because they behave like the devices Findy looks for. A smart television or streaming stick handles video, publishes Bonjour services and often listens on port 8080 or 8008. A network printer publishes services and serves a web interface on port 80 or 443. Speakers, consoles, thermostats and access points do similar things. The port and service indicators that suggest an IP camera are the same ones ordinary media and web-facing equipment uses, so Findy shows the evidence and lets you judge rather than pretending it can tell them apart.
Crowded networks
In a hotel, a hostel, a block of flats or a co-working space, the list can run to hundreds of entries: every guest's phone, laptop, tablet and watch, plus the building's own equipment. That volume is normal and tells you nothing by itself. Judge individual entries, not the total.
iOS does not expose the ARP table, so Findy cannot read hardware addresses or look up a manufacturer. The inventory is keyed by IP address, which the router may reassign — so a device you already dismissed can reappear at a different address and be badged as new.
Bluetooth
Any advertising Bluetooth Low Energy device in range appears: headphones, watches, fitness bands, televisions, speakers, car systems, tags on other people's keys, and equipment through the wall in the next room. Signal strength is affected by walls, bodies, orientation and battery level, so a "strong" reading can come from a device further away than a weak one.
Findy's background following detection is the more meaningful Bluetooth signal, because it looks for the same device reappearing across different places rather than merely being nearby once.
Magnetic-field readings
What causes magnetic-field false positives?
Almost everything with metal or a coil in it. Speakers and headphones, motors and fans, chargers and cables carrying current, fridge magnets and magnetic catches, structural steel and reinforced concrete, radiators and appliances, laptop and tablet lids, and magnetic phone cases, rings and car mounts. Building wiring shifts readings as well. A magnetic deviation tells you there is metal or a magnetic field nearby, which is true of most furnished rooms, so it is only meaningful when you compare one specific object against a baseline you took away from electronics.
Taking a reading that means something
- Remove your case, magnetic mount, ring and any accessories from the phone first.
- Take a baseline well away from electronics, wiring and metal furniture.
- Sweep one specific object slowly, not the room.
- Compare several sides of the object rather than one face.
- Repeat to confirm the reading is stable rather than a passing spike.
- Unplug the object if you safely can. A reading that disappears with the power was the current.
Deciding whether something is actually worth investigating
Use this as a triage order. Most flags stop at step one or two.
Points towards ordinary
- You can identify the physical object and it is obviously what it looks like
- The reading disappears when the object is unplugged or the remote is idle
- Only one method flagged it, and only weakly
- The network entry behaves like media or printing equipment
- The room is full of similar entries with the same profile
Points towards worth checking
- The object has no reason to contain electronics but reads like it does
- An object is aimed at a bed, shower, changing area or desk
- Two independent methods point at the same physical spot
- A network entry advertises a video service and carries a camera-suggestive name
- The result repeats consistently across several scans
Ruling out false positives does not mean the room is clear. A powered-off device, a camera on another network, a wired camera with no radio and a passive microphone all remain invisible to these methods. See the honest limits.
If you think Findy labelled something incorrectly — in either direction — tell us what it was. Concrete examples are what improve the labelling.
Last reviewed 2026-07-23 · Written and reviewed by the Findy developer.