A self-powered switching device using a prestressed flextensional electrocative member (12) generates a signal for activation of a latching relay (90). The electroactive member (12) has a piezoelectric element with a concave face that may be compressed to generate an electrical pulse. The flextensional electroactive member (12) and associated signal generation circuitry (10) can be hardwired directly to the latching relay (90) or may be coupled to a transmitter (60) for sending an RF signal to a receiver (70) which actuates the latching relay (90).