Incredible Traffic Light

You show two cards: one is completely black, while the other has three colored spots representing a traffic light: red, yellow, and green. These cards are each placed in a transparent plastic sleeve.

The spectator can now open their hands, you remove the two cards from their sleeves and place them face down in their hands. With a wave of your magic wand, the green spot mysteriously disappears and appears on the other card, all while in the spectator's hands! The trick comes with instructions in English, but it is very easy to learn.