Start by taking a deck of cards and tell the audience that you have made a prediction that is in your inside coat pocket, tapping your chest to indicate where it is. You proceed to let a spectator choose a card, and then show you have predicted it by removing from your pocket a Jumbo Eight of Diamonds. 

The spectator protests that this is incorrect, so you ask for the name of the card chosen. "The Jack of Spades" you are told. "In that case I must perform what is called in the trade, a switch." you turn the card around and fixed to the back is a wall switch, you solemnly flip the switch. When you turn the card around again, it has now changed to the correct card, the Jack of Spades.

Includes instructions

Condition: fine