Q: How many Unitarian Universalists does it take to change a light bulb?
A: ...well, first you'd have to know whether it's a fluorescent, an incandescent, or a halogen bulb, but even then you may have made a false assumption because not all Unitarian Universalists necessarily even find lightbulb-oriented illumination useful, or even believe in Electricity or the Electric Company.
ROFLMAO - My uncle was a Unitarian. I'm assuming based on your joke you knew him!
Q. What does the Ku Klux Klan do when a Unitarian moves to town?
A. They burn a question mark on his lawn.