"Three blondes are attempting to change a light bulb" joke

Three blondes are attempting to change a light bulb. One of them decides to call 911:
Blonde: We need help. We're three blondes changing a light bulb.
Operator: Hmmmmm. You put in a fresh bulb?
Blonde: Yes.
Operator: The power in the house in on?
Blonde: Of course.
Operator: And the switch is on?
Blonde: Yes, yes.
Operator: And the bulb still won't light up?
Blonde: No, it's working fine.
Operator: Then what's the problem?
Blonde: We got dizzy spinning the ladder around, and we all fell and hurt ourselves.