The switch has a socket with a support ring for insertion in a wall opening, fitted with a cover frame (2) incorporating a switch cover (13) having a key card entry (4), in which the key card (26) is inserted for operation of a switch wiper mechanism. A frame (3) positioned beneath the switch cover has an insertion opening (7) for the key card and a spring elastic switch lever (8) acted on the inserted key card and in turn acting on the switch wiper (10) of the switch wiper mechanism, to bring a contact wiper (20) into contact with a stationary contact (19).
