Abstract: A signalling mechanism includes a switch having a handle manually movable between first, second and third positions. The switch controls the operation of a light to be attached to it, a porch light or yard light, for example. A circuit interrupting device is activated when the switch is the second position and intermittently illuminates the light. The mechanism also has a position indicating device, a small lamp for example, which is controllably activated for indicating a position of the switch. The signalling mechanism is constructed and arranged to be received in a standard switch outlet box.