Abstract: A switch adapted to cooperate with the pull-down claw of a silent movie camera for transmitting an electrical signal each time a frame of movie film is advanced past the shutter of the camera includes an insulating base adapted to be positioned within the film receiving compartment of a movie camera so as to fit around the film gate, the base having a grounding contact arm engaging the gate so as to be grounded through the camera and a contact finger insulated from the gate and disposed for intermittent engagement with the reciprocating pull-down claw which serves to close the switch each time a frame of film is advanced past the shutter.