Elisa DeCarlo

This is a wonderfully silly story about a man who can see ghosts who ends up becoming a paranormal detective. In the same vein as Jeeves and Wooster, except with supernatural overtones.

It's been 12 or 13 years since I last read this, but I remember enjoying it immensely at the time. Very funny. The hero, Aubrey, reminds me of Bertie Wooster, only with psychic powers.