Spending a night in America's most haunted asylum doesn't sound like fun, does it?
I guess it depends on how brave you are.
But for these YouTubers, there came a moment in their exploration that nearly sent them running for the hills.
YouTube/Yes Theory)
The YouTube channel Yes Theory visited the infamous Pennhurst State School and Hospital.
Opened in 1908 near Spring City, Pennsylvania, the building was run for mentally and physically disabled people living in the area.
However, abuse of patients was rife within the hospital.
This was exposed in a 1968 documentary, and the hospital closed 19 years later.
In the years since, the site has garnered a reputation for being haunted by the spirits of its inhabitants.
Which makes it a particularly spooky spot for a team of ghost enthusiasts.
But is this place too scary even for them?
The spine chilling moment came when they sent out 'good vibrations' to anyone who had suffered in the building.
Their REM machines began beeping immediately.
YouTube/Yes Theory)
Ghost hunters use these devices to detect small breaks 'in the magnetic field'.
In other words, they make a noise whenever something changes in the air.
And it made a ton of noise when set up by a closed door.
At one point, the team were convinced that a spirit had told them to 'stop it'.
"I don't find it cool or fascinating at all," one of the YouTubers said.
"If a spirit yells at me to 'stop it', I'm going to stop it."
This same guy even admitted that he's usually not prone to getting jittery at the idea of the supernatural.
He admitted: "I'm usually a sceptic until I step into it.
"Then I give in, I believe."
It's believed that the primary ghost in this equation was a particularly abusive doctor who had tormented a lot of the patients under his care.
One of the hunters expressed their view that he was the only spirit they would call 'mean'.
The basement of the hospital plays host to a ton of creepy looking dolls, one of which had ominous red eyes.
YouTube/Yes Theory)
There was a ton more noise down there too - and one guy even agreed to staying down there by himself.
His attempts to get a reaction out of the ghosts didn't produce much in the way of results, however.
But the sound of dripping water in the difference would be enough to spook anyone.
All in all, this is not a place any of us would be rushing to visit in a hurry.