Because who in their right mind would stick a piece of metal in an electrical socket *unconsciously rubs lighting bolt scar running up forearm* this is a video demonstration of the hidden wall safe that requires a user to stick a key in one of the type J outlet holes in order to unlock it. Just don't get too drunk and forget which outlet in your home is the hidden safe, or you might have to spend the rest of your life with electricity based superpowers. And who wants those? *chargers electric car in an instant, solves world energy crisis* Just kidding, I really only use them to electrify the urinal when a friend is peeing.
Thanks to Alexander S, who agrees the next time you're looting an enemy's home, don't forget to tear out all the walls with a pickaxe looking for hidden safes.