Frequent travelers often carry small Radio Frequency (RF) detectors that beep when they pick up a signal from a wireless camera.
Experts note that miniature "pinhole" cameras are increasingly accessible and inexpensive, making them a tool for illicit Voyeurism.
Look for "off" objects. Are there two smoke detectors? Does a coat hook feel loose or look thicker than usual?
If you must remain in the room, hang a piece of clothing or a bag over the lens until help arrives.
Security experts suggest a few quick "sweeps" you can perform whenever you enter a private trial room: