A signal repeater for receiving and re-transmitting signals from environmental transducers and the like, and for mechanically and electrically cooperating with existing electrically powered fixtures. More particularly, the present invention includes a housing unit for mechanically and electrically coupling to the powered fixture, a transceiver unit, and a first power supply electrically connected to the transceiver circuit and housed by the housing unit. The repeater is adapted to maintain the functionality of the fixture.