Focus on the whole mirror assembly and what it can see. Popular fingernail tests are not reliable proof of a two-way mirror or camera.
Inspect the frame and surrounding wall
Look for holes, wires, unusual gaps, electronics, and objects aimed through or around the mirror.
Dim the room and use angled light
Sweep a flashlight across the mirror edges and nearby objects. Inspect sharp reflections at close range.
Evaluate location and access
A suspicious mirror needs a useful view and space behind it. Consider whether the wall backs onto another accessible room.
Frequently asked questions
Does the fingernail test work?
No. The gap depends on how the reflective coating is manufactured and does not prove surveillance.
Can a camera record through a normal mirror?
A camera may be hidden in the frame or behind specially prepared glass, but ordinary mirrors are opaque.
What should I do if I find a lens?
Do not touch it. Photograph the location, leave the room, and contact management or authorities.