Before someone can enter the “survival horror challenge” of McKamey Manor, there’s a physical exam. Then there’s a background check, a phone screen, a 40-page waiver and a drug test. If all that goes according to plan, participants have to watch a nearly two-hour documentary featuring every person who has attempted the haunted attraction in the past two years.

McKamey Manor, based in Summertown, Tennessee, bills itself as "an audience participation event in which (YOU) will live your own Horror Movie."

“Understand that each tour will be different based upon your personal fears, and can last up to 10 HOURS,” the website says. “Each guest will be mentally and physically challenged until you reach your personal breaking point.”

An online petition with tens of thousands of signatures says it’s all a front for a torture chamber and urges state officials to shut down the attraction.

The complicated screening process for McKamey Manor is meant to select participants who can be easily manipulated as the attraction’s cast duct-tapes their heads, forces them to eat things and waterboards them, according to the petition, which had been signed by more than 67,000 people by Wednesday afternoon. The petition also claims that founder Russ McKamey hires employees with violent histories and makes people ingest pills that cause hallucinations.

“It’s literally just a kidnapping and torture house,” the petition says. “Some people have had to seek professional psychiatric help and medical care for extensive injuries.”

McKamey told The Washington Post that he didn’t “want to confirm or deny which areas are real and which are not” from the petition but that no torture or illegal activities are part of the experience. Law enforcement keeps a close eye on the manor, he said, and he calls police to warn them before each new participants begin the tour in case they get reports of problems.

McKamey said he does, however, use psychological techniques to convince people that they are experiencing things that they are not. He said he films every visit so he has proof of what happened and didn’t happen during it.

“There’s no torture, there’s nothing like that, but under hypnosis if you make someone believe there’s something really scary going on, that’s just in their own mind and not reality,” he said.

Hundreds of haunted house attractions alarm and delight Americans each year, particularly around Halloween. “Extreme” haunted houses, which aim to terrorize through physical and psychological stress, are less common. They are often subject to fierce criticism, while thrill-seekers line up for the chance to be scared out of their minds.

Since a story about the manor from WFLA-TV this month made waves online, McKamey said he has kept his phone on “do not disturb” mode because thousands of people have been calling to set up visits. He said the attraction has a long wait list.

The manor, he said, is an interactive experience that relies on mind games meant to make people believe things that aren’t really happening. He said people are not really waterboarded, for example, but he uses hypnosis and other mind-control techniques to put that thought in their heads.

"If you're good enough and you're able to get inside somebody's noggin like the way that I can," McKamey said, "I can make folks believe whatever I want them to believe."

McKamey, who said he served in the Navy for 23 years and moonlights as a wedding singer, started the manor 30 years ago as a cross between his theatrical background and his love for haunted houses. In all that time, he said, no one has completed the manor experience.

Reservations are required to tour McKamey Manor, and only one or two people are allowed in at a time. Participants have to be over 21, or between 18 and 20 with a parent’s permission. Guests who are pregnant or claustrophobic, or have seizures, or respiratory or heart problems, are urged not to participate. The cost of admission is a bag of dog food for McKamey’s five dogs.

Participants start the tour with the chance to earn $20,000 and lose $500 every time they fail an activity, McKamey said. He also takes away $500 if a guest says a curse word, since cursing is not allowed at the manor.

“I’m like the most strait-laced guy you could think of, but here I run this crazy haunted house,” McKamey said. “And people twist it around in their little minds.”

McKamey said he has invested more than $1 million in the attraction, which is a mobile experience. Guests start in Summertown, but McKamey said he transports them to different locations in Tennessee and rents other people’s farms and abandoned buildings for the stunts.

If participants lasted long enough in the experience, McKamey said they would end up in Huntsville, Alabama. No one, however, has ever gotten that far.

“It really is a magic act, what I do,” he said. “It’s a lot of smoke and mirrors.”

Marisa Iati of The Washington Post wrote this story.