None. There never was any light bulb.
Notes: Probably the only really good light bulb joke of 1984.
or
When it came time to pay, the skunk didn't have a scent, the deer didn't have a buck so they put the meal on the duck's bill.
or
Actually, agents will screw in just about anything.
or
Your breath!
or
The players dribble a lot.
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Because it goes good with chips.
or