A crossing guard.
or
Finding a cabinet position for the thing on his head!
or
Just one, but he/she will spend hours checking for technical problems.
or
Two — one to change the bulb, and one to write a song about how good the old light bulb was.
or
A centipede with a wooden leg.
or
They're both plastic and little boys turn them on.
or
None. Agnostics question whether electricity really exists.
or
One, but she'll be on the phone for five hours telling all her friends about it.
or