Vampires. Werewolves. Chained-up skeletons hanging from the walls. Well, it's just another day at the office for John Denley.

Denley, 41, is president and owner of Boneyard Productions, a haunted-house consulting company in Salem, Mass., site of the notorious 17th-century witch trials. His projects have included turning Madison Square Garden into Madison Scare Garden, and he also works with theme-park owners to create their own creepy attractions.

Turning an empty warehouse into a frightening -- and safe -- haunted house isn't easy, he said. It also isn't cheap. Denley said he lost his shirt on his first three professional haunted houses. "I didn't really know how to put a value on what I was doing."

He does now: He charges $100,000 and up for a typical, 3,000-square-foot haunted house.

It's a niche business, and Denley said he only has a handful of serious competitors, nationwide.

Unfortunately for other aspiring haunted-house designers, there's no ghoul school to learn the trick-or-treats of the trade. Denley previously worked as an engineer, but his love for horror goes back to childhood, when he would turn his own home into a haunted house, attracting hundreds of kids to the show.

"Christmas was always great, but it's nothing like Halloween," he said.

-- Mary Ellen Slayter

John Denley's Boneyard Productions is a haunted-house consulting company.