Matchbox Mambo trick
"Two matchboxes are shown and the drawer of one box is opened and they are placed end to end. When the drawer is pushed shut, the drawer of the other box opens! The boxes are held in several different ways, each more baffling than the time before, and the drawers still open and close! The boxes defy the laws of nature in an incredibly magical manner. The boxes can be minutely examined by the spectator and there is nothing to see! This is one of my favorite effects. Easy to do yet unbelievable to see."
Danny Archer Magic