Just like the effects where magicians on TV reveal a prediction made while the people at home participate in the trick.
Nine cards of different occupations are placed on the table. The spectator places an envelope on one card, lets say The Bee Keeper. They read off how many spaces to move the envelope and an occupation card is removed. This is repeated several times until only one occupation remains. When they open the envelope, it matches the remaining card! Self-working.
NOTE: This is an "open box" item. The trick was opened, inspected and set aside. It comes complete.