When [the-rene] was building an escape room, he decided to have a clue delivered by radio. Well, not exactly radio, but rather an old-fashioned radio that lets you tune to a faux radio station that asks a riddle. When you solve the riddle, a secret compartment opens up. [the-rene] says you could have the compartment contain a key or a clue or even a cookie.
The outer case is actually an old radio gutted for this purpose. In addition, a laser cut box and a servo motor form the secret compartment.
