William Earl Horror Film School is a feature in which talent in front of and behind the camera share the ins and outs of creating the biggest onscreen scares. “Suitable Flesh,” the newest film from “Mayhem” and “Point Blank” director Joe Lynch, is an unconventional tale. The movie, a modern spin on H.P. Lovecraft’s short story “The Thing On The Doorstep,” is headed to theaters and VOD Friday, and can best be described as a gory body swap dark comedy styled after ’80s erotic thrillers.