Another prop often used by clients are lapel microphones that can be dangerous. We had three embarrassing moments with President Reagan when we had been told the Mic's had been turned off, and they where not. In the end I always used our TSCM equipment to insure they were indeed off. With out the equipment, the safest bet is to take it off the client. Still watch for them taking emergancy info by phone or even in person from staff. Just putting your hand over the mic, will not work. On two well used systems, just pulling out the mic jack from the transmitter will not work, the transmitter has it's own internal mic. It is best to review any equipment like this that is around the client. In many cases when the Press setup microphones on the speakers podium, they are also hot. So staff running up to check them can be heard talking most of the time. Be very careful of both microphones as well as cameras. A lot of board rooms are set with cameras and mic's that are always on, please check. By the way your cheap little RF detector will often catch wireless mic's that are still on, to include cell phones left on at the podium. More and more press are using cell phones as backup podium mic's just be careful.