Sometimes the best place to hide something is where people least expect it, so in this project, we're making a super secret safe that only you'll know about.
You'll need either a single- or double-gang plastic, old-work, electrical box made for existing walls, depending on how much stuff you have to hide. Also, you'll need a blank wall plate or receptacle cover (with receptacle) that matches the ones in your house already. Click here for a complete parts list.
I saw a picture of a hidden wall safe on LifeHacker and found it was a product being sold for about $8.00 from ThinkGeek, but rather than order one, it seemed feasible to make one with just a couple of materials from the hardware store. Not to mention, much cheaper.
There are so many variations that could be done with this idea. I demonstrated four that I came up with in my video—a single-gang box with blank cover, single-gang with receptacle and cover, double-gang with receptacles and cover, and a preexisting cable outlet box.
Perhaps the best one was the fact that you could just use an existing coaxial cable box in your wall. Just look around for one of those cable jacks around your place.
If you use one of those, it's completely free, and you don't have to cut any new holes in your drywall. The cable is protected, there's plenty of space inside, and it's a great place for hiding small things, like your list of computer passwords.
If you choose to use a cut-in box, extreme caution should be used when cutting into sheetrock. There may be electrical wires or other sensitive materials behind the wall that can't be seen and could be damaged when cutting.