Retro 1972 "3M Brand Intruder Alarm - Model 451", disguised to look like an "English Language Dictionary". It measures about 8.25" x 6" x 3" and plugs into a standard household electrical socket.

We're not sure how to set this up, but we've plugged a lamp into the socket on the back and the lamp turns on / off when we switch the operating mode from alarm to light. We're selling this for repair or parts.