An electromechanical switch actuator operated by a detachable, mechanical key providing security against unauthorized operation. The switch actuator disclosed is of particularly rugged construction, arranged to provide rotary torque for operating axially coupled electromechanical rotary switches having a plurality of switch banks or stacks disposed along a central axis. Switch operation is provided for any predetermined number of switch positions with non-electric indication of said positions, both by visual observation of the key entry area, and the key position. Key operating forces are converted entirely to rotational torque for switch operation and positive rotary motion limits independent of the electrical switch provide substantially increased switch life.