To say that ghosts are making a comeback has a redundant ring, sort of like beating a dead horse. But in movies, the concept of visible, audible phantom life is thriving again, enough to stir the ectoplasm of even the most moribund spirit. Ghost Dad is only the newest incarnation of the phenomenon. In recent months we’ve also had Always; soon we’ll have Patrick Swayze in Ghost and Mark Harmon doing haunting of sorts in Cold Heaven. Probably the best known (and most entertaining) cinematic apparitions, Cary Grant and Constance Bennett in the first Topper, date back to that heyday of creative escapism, the ’30s. But then there were Spencer Tracy in A Guy Named Joe and Charles Laughton in The Canterville Ghost during World War II, Edward Mulhare in the ’60s TV series The Ghost and Mrs. Muir and James Caan in 1982’s Kiss Me Goodbye. The equivocal characters in Ghostbusters don’t really count, but Casper the friendly ghost does. The idea of being able to hang around and kibitz after we die is an irresistible fantasy, and the philosophical boneyard hasn’t been made that can contain the concept of wishful thinking.