The Fairly OddParents S05E30 - Presto Change-O

Timmy wishes for a joy-buzzer that allows him to swap bodies with whoever he touches. Wanda is hesitant to grant the wish at first, since Timmy wants to use it to swap bodies with A.J. and cheat on a test, but she has to grant the wish anyways when Cosmo rushes her to Fairy World to help take care of Mama Cosma, who catches the nine-hour flu. This means that Timmy is without his fairies for nine hours, and when he accidentally switches his body with Mr. Crocker's, he must get his body back before Crocker tricks his fairies into revealing themselves to him. At the end, Cosmo and Wanda return just in time to return Timmy back to his body.