Do you want a way to make sure light switches are in the "off" position?
Do you want your room to look like a missile command room?
Do you want to accidentally avoid turning on a switch?

If any of these are true (or even if they aren't), you can also print a cover for your standard US wall light toggle switch!

(Couldn't get the other models I found to work smoothly, so designed my own from scratch.)

Edits:

• [2022-02-02] Added “SwitchGuard_SmallerNubs" – For those that are having issues snapping the two pieces together without breakage. The nubs are a little smaller, with the tradeoff that it may be a little looser.
• [2022-02-02] Added “SwitchGuard_PiP_untested" – Alternatively, try printing-in-place. Use support-from-plate!  (Have not tried printing it, but the slicing paths look correct.)
• [2022-02-02] Added “SwitchGuard_Lock” – For those that just want a cover (aka allow always on).