From the ArcaMax Publishing, Jokes Newsletter:
http://www.arcamax.com/news/jokes/s-381648-562204
A man was walking in the street when he heard a voice. "Stop! Stand
still! If you take one more step, a brick will fall down on your head
and kill you." The man stopped and a big brick fell right in front of
him. The man was astonished.
He went on, and after awhile he was going to cross the road. Once
again the voice shouted: "Stop! Stand still! If you take one more step
a car will run over you and you will die." The man did as he was
instructed, just as a car came careening around the corner, barely
missing him.
"Where are you?" the man asked. "Who are you?"
"I am your guardian angel," the voice answered.
"Oh yeah?" the man asked. "And where the heck were you when I got
married?"