On our old style switches used to have a light switch lock on several of them [https://www.thingiverse.com/thing:69806.](https://www.thingiverse.com/thing:69806.) Thes worked great but no good on rocker/toggle switches. Saw a few designs but wasn't a big fan so designed my own in F360.

With these covers you can't accidentally turn On/Off the switch but you can easily do it on purpose by pushing something through the relevant hole.

There are two versions with holes in further or nearer apart and a child-proof one with much smaller holes