A thermal imager does make detection of most electronics very easy if they're powered on: https://www.beneaththewaves.net/Photography/Images/Thermal_Imaging_Ex

A thermal imager does make detection of most electronics very easy if they're powered on: https://www.beneaththewaves.net/Photography/Images/Thermal_Imaging_Examples-06-Hidden_Cameras-Hidden%20Cameras-02.JPG https://www.beneaththewaves.net/Photography/Images/Thermal_I... When I travel, I use mine to sweep the room.