A guy walks into a dentist office:
Dentist: How can I help you today?
Guy: I'm a moth.
Dentist: Excuse me?
Guy: I'm a moth.
Dentist: Hmm. Well, I'm glad you came to see a doctor . . . but sir, I don't think I'm the kind of doctor you need. I'm a dentist--I think you may need to see a psychiatrist.
Guy: I'm a moth.
Dentist: Ok, you're a moth. But why did you come here?
Guy: Your light was on.