William Henry Harrison
If I’m not much mistaken, William Henry Harrison and Casper the ghost both died of pneumonia, that is, if the 1995 movie Casper the Ghost is to be believed (about Casper. I do not recall the movie addressing William Henry Harrison’s death). In an unnecessary bit of back information, Casper remembers dying because he played in the snow too long, probably to get the weaklings in the audience emotional. Where was I? Oh, right, William Henry Harrison’s ghost haunts the White House with good natured hijinks.