None. The darkness will cause the bulb to change by itself.
or
Does it have to be a light bulb? I've got this neat candle holder...
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Silly, WASPs don't screw in a light bulb, they screw in a hot tub.
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Because the sea weed
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The players dribble a lot.
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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