Manhattan Repertory Theatre has struck theatrical gold with Tim Mulligan’s wickedly entertaining “Point Loma,” a gleefully campy horror spoof that channels the best of 1950s B-movie schlock while delivering genuine scares and belly laughs in equal measure. Under Ken Wolf’s spirited direction, this off-Broadway gem transforms the intimate black box space of the Chain Theatre into a haunted playground where paranormal podcasters meet their match in a sinister San Diego hospice house.