SEATTLE - At the American Cancer Society's Seattle headquarters, it seems cancer isn't the only scary thing the staff deals with on a daily basis.

Before it belonged to the ACS, the nearly one-hundred-year-old Queen Anne building was home to a children's hospital and a morgue.

Now, a group of ghost hunters believe it's haunted.

"There's some really strong evidence. There's so many people that have had so many different experiences, it's pretty interesting," said June Nixon.

Nixon's with The Advanced Ghost Hunters of Seattle/Tacoma, one of the oldest paranormal investigation groups in the Pacific Northwest.

AGHOST has been studying the American Cancer Society's Seattle headquarters for the last decade. They revisited the building this week, just days before Halloween.

"We like the creepiness of Halloween," said Dan Pruett, another AGHOST investigator. "I think it takes a special person to come into a completely dark area, senses heightened, and try to talk to ghosts and not freak out."

Pruett said they've spent hours inside the ACS building, armed with audio recorders and infrared cameras. What they're looking for are the five seconds that can't be explained.

ACS employees say they've seen plenty of it.

"In this office, I've heard a lot of weird sounds. Gurgling, moaning, talking, and there's no one there," said ACS employee Steve Hedlund.

Hedlund says he's even felt the ghosts tug on this shirt on several occasions, as he walks down the hall. But he's never felt afraid of them.

"They're not dangerous, they don't bite or hit or anything, so it's not like a poltergeist," he said.

Others like to think of them as friendly ghosts, haunting the American Cancer Society headquarters because they believe in the work that is done there.

"I think cancer is scary," said ACS Communications Manager Christina Kelly. "And if there is any sort of presence here, I think they're aligned with what we're doing. Cancer is scary, and we're going to do what we can here to help patients."

The American Cancer Society helps fund cancer research and provides resources and support to cancer patients and their families.