The shortest-serving President in U.S. history was William Henry Harrison. Ever heard of him? I hadn't. He held office for 32 days. On the last day he died of pneumonia. It was April 4, 1841 and many say that he couldn't let go of the fact and like any good ghost, move on. White House residents claim they can hear Harrison rummaging in the attic, looking for something.
There's word that he's not alone. A security guard for President Truman once heard a voice coming from the attic above the Oval Office, saying, "I am David Burns." Burns was a cheated man. In 1790 he was forced to give up his land, which is where the White House now stands.