Abstract: An arrangement for preventing operation of an electric switch includes substantially pin-shaped male formations rigid with the switch and substantially socket-shaped female formations which are mounted on spaced mounting portions of a protecting element and which engage the male formations with snap action. The protecting element for use with a wall-mounted toggle switch has a strip-shaped configuration and its central portion located intermediate the mounting portions outwardly hugs the trajectory of pivotal movement of the actuating member of the switch. Two lugs may extend from the central portion toward the switch at the opposite sides of the trajectory of movement of the actuating member. The male formations may be mounted on connecting screws which connect a cover plate of the switch to a bracket which carries a switch housing and is mounted on a switch box.