Jon always wanted to switch with someone else's life. Particularly, a woman. He had the perfect person in mind and decided to go for it.
"I wish I would switch my life with ..."
Then, all of a sudden, someone knocked on the door. "Jon? Are you in there?" It was Karyn.
Not thinking about what he was just doing, he yelled out "Karyn, I'll be out soon."
He then thought about his wish he was making and realized that he had just wished to switch with Karyn. But there was nothing he could do about it.
The wishing stone glowed. And when the light dissipated, Jon saw that ...