I'll meet you at the corner.
or
Because it goes good with chips.
or
None, because people who glow in the dark don't need light bulbs.
Note: Topical to the Chernobyl Reactor disaster of 1984.
or
Silly, WASPs don't screw in a light bulb, they screw in a hot tub.
or
One. No, two. No... How many do we have on the truck?
or