If you can press a button, you can perform The Chest.  Have a spectator write a secret message and fold the paper. Open the chest and it bursts into flames.  You or the spectator toss the message into the chest for the flames to consume the secret and you secretly retrieve and reveal the secret. Requires  lighter fluid and Flash Cotton. This is just ONE idea for the chest.  All electronic and silent working, made of wood.  12 x 8 x 8 cm approx.