Locking Industrial Grade, Toggle Switches, General Purpose AC, Single Pole, 20A 120/277V AC, Back and Side Wired Key Guide, Packed with Key | 4901L | Bryant
Leviton 15A Brown Lock Switch plus Key - 1201-2L
The No Screw-Ups Key Hook Organizer. Installs in Seconds on Any Light – Mount Genie
Pass & Seymour, 500K, 1 Piece Locking Light Switch Key, For Heavy Duty Locking Switch "I" Series - Newegg.com
This lightswitch-like thing with a slit in it. On the bathroom wall in my office. : r/whatisthisthing