Sometimes hiding things in plain sight can be better than placing it in a thick safe. Place your precious jewelry into this fake wall outlet and thieves will never find it. There's also a lock mechanism to keep the outlet from falling out willy-nilly.
The only problem with this is the ground hole on the outlet is on the top instead of on the bottom, which makes the burglar's game of "which one is different from the rest" quite easy.
Update: Reader Chad tells us the invertedness may be intentional:
I just started to do some house hunting and notice this in the newer houses. The ground on top is to represent a outlet controlled by a light switch.