Cole Hersee Toggle Switch Guard, Part No. 82468-BX

Spring-loaded snap action holds the Switch Guard positively in the up or down position. On returning to the down position, the Switch Guard cover automatically moves the handle of the switch to the down positition (usually off),  and secures it in that position. The switch cannot be operated with the cover down. It’s easily added to an installed switch by simply unscrewing then replacing the switch face nut.