A locking device for a standard toggle light switch is disclosed. The locking device has a partial rectangular cuboid member, a planar torque arm member, a planar locking member, and a locking tab with a notch. The planar locking member inserts into an interstice at the base of the rotary hub of a standard toggle light switch. The locking tab fits into another interstice along the side of the rotary hub and engages with the toggle housing, locking itself in place.