I don't waste my time with these childish jokes.
Just one. He holds the bulb and the room spins.
One
None, that's what interns are for.
None. Babies don't have the motor skills or the depth perception to change a light bulb.
Two of my favorites are:
You wouldn't want to get repossessed!
There's a limit to how many characters you are allowed to waste.
They know resistance is a waste of energy.