Mercury Matchbox by Mark Southworth

The card box is on the table in full view of the spectator. A card is freely selected, signed and returned to the middle of the deck. The performer announces that the card is no longer in the deck, and that it is now in the card box.

The spectator opens the card box and empties out the contents. To their surprise there is a matchbox inside. The performer takes the matchbox, opens it and unbelievably reveals that there is a folded up playing card inside. The performer tips it out, and proceeds to unfold it. It is the spectators signed card!