Ghost in the Darkroom

From The New York Times:

IT is not a place you would normally expect to find a curator preparing for a major photography show at the Metropolitan Museum of Art. But a few summers ago, Pierre Apraxine was camped out on the third floor of a rambling town house on West 73rd Street near Central Park, the headquarters of the American Society for Psychical Research, a 120-year-old repository of the paranormal whose founders included the philosopher William James.

Excellent article. Also click on the link to go to a spectre-acular slide show of spectral portraits.