Comment by SudoEpoch

Cameras are easy to find. You use red glasses (laser safety ppe) and a red light source. The type of polymer they coat lenses in is highly reflective in the red spectrum. With out getting into too many details you just shine the light around looking for strong pin pricks of red light. I've got experience doing this for over 20 years and this is by far the most effective approach 100% of the time.