must_know:
A lady was expecting the plumber; he was supposed to come at ten o'clock. Ten o'clock came and went; no plumber; eleven o'clock, twelve o'clock, one o'clock; no plumber.
She concluded he wasn't coming, and went out to do some errands. While she was out, the plumber arrived.
He knocked on the door; the lady's parrot, who was at home in a cage by the door, said, "Who is it?"
He replied, "It's the plumber."
He thought it was the lady who'd said, "Who is it?" and waited for her to come and let him in. When this didn't happen he knocked again, and again the parrot said, "Who is it?"
He said, "It's the plumber!"
He waited, and again the lady didn't come to let him in. He knocked again, and again the parrot said, "Who is it?"
He said, "It's the plumber!!!!!!!!"
Again he waited; again she didn't come; again he knocked; again the parrot said, "Who is it?"; "Aarrrrrrgggggghhhhhhh!!!" he said, flying into a rage; he pushed the door in and ripped it off its hinges. He suffered a heart attack and he fell dead in the doorway.
The lady came home from her errands, only to see the door ripped off its hinges and a corpse lying in the doorway, "A dead body!" she exclaimed, "Who is it?!"
The parrot said, "It's the plumber."
Original Source