Joke: How Many Electrical Engineers?

Q: How many electrical engineers does it take to screw in a light bulb?

A: None. They'll be so busy trying to figure out why the light won't turn on that no one will think to check the light bulb.

Source: I came up with this joke after I did something similar, but with my cordless mouse. I was sure there was something wrong my computer so I shut it down, checked all the cables, rebooted - only to discover later that the batteries in my mouse were dead.