Since moving into a Brooklyn Heights apartment occupied by author H.P. Lovecraft in the '20s, a pair of roommates have been having some weird experiences. A picture "mysteriously leaped off" the wall, the hammer used to hang the picture disappeared, a Ouija board seance really freaked everybody out, and a humming noise has gone unexplained. One of the tenants, Nellie Kurtzman (daughter of famous Mad Magazine founding editor Harvey Kurtzman), tells the Post she doesn't......