Hidden Wall Safe $4.99 at Bed Bath &amp; Beyond stores    It looks like an ordinary wall socket, but it&#39;s actually a mini wall safe. The compartment behind the socket is the perfect place to keep money, jewelry and other valuables. Easy to install. Measures 7 3/4&#34; L x 3 1/2&#34; W x 2 3/4&#34; D. One-year limited warranty.