In this fun and easy project (which originally appeared in the Spy Tech edition of Make Magazine), you’ll connect a shirt-pocket “amplified listener” hearing aid with an in-car FM transmitter to create a wireless bug. Then you’ll tuck them inside a hollowed-out book with the microphone (mic) concealed by the dust cover, and you’ll have a covert listening device that you can leave lying around or on a shelf near a surveillance target. Then you (or an undercover agent) in the next room can eavesdrop on any devious plotting through an ordinary FM radio.