Maybe it isn't your imagination. Maybe that sense you weren't alone when you actually were, or that human-like shadow you saw when no one was there wasn't just your mind playing tricks on you.

It could be that the goosebump-inducing feeling is the result of some semblance of paranormal activity.

At least, that's what Ryan Buell and his team are out to investigate. Buell is the director and founder of the Paranormal Research Society (PRS) at Penn State, and his team's investigations have become the subject of the A&E program Paranormal State, which will premiere in December.

"The majority of the cases we do deal with people who feel like they're experiencing a haunting, so a lot of what we do is like being a counselor," Buell said. "Regardless, if it's paranormal or not, their fear is real -- they're frightened of something."

Buell founded his club in an area that's rich in stories -- whispered tales of ghosts and haunted buildings. This allowed his team to hone their paranormal investigatory skills without going too far. Some on-campus buildings in particular are the subject of such tales year after year: the Pattee Library, the Schwab Auditorium and the Old Botany building are the major ones.

The Pattee Library

In late November of 1969, Betsy Aardsma, a 22-year-old graduate student at Penn State, was researching a paper for English 501 on the second level of the Pattee Stacks, according to a 1989 article in The Daily Collegian. Her life was ended there by means of a stab wound to the heart, according to forensic pathologist Thomas J. Mangani. It was ruled a homicide, and the killer was never caught.

"I don't think she's haunting that place; I think that's just a fear," Buell said. "But people definitely claim there's something else there."

Buell's attempts at investigations in the Pattee Stacks have been fruitless because he said the library won't allow it in order to avoid the publicity. He said he gets e-mails all the time from "legitimate people," including library staff, telling him stories ranging from seeing a "person walk through a wall" to girls saying they were accosted by a male figure who would "suddenly vanish."

Maybe there is some merit to all these stories about the Pattee Library -- or maybe it's just an excuse not to go to the library.

The Old Botany Building

Old Botany is a tall, skinny building right across from the Schwab Auditorium, and it's also one of the oldest buildings on campus, Buell said.

Buell said the rumor is that the late Mrs. Atherton is buried in the attic, and she watches over her husband who is buried across the street, right next to the Schwab Auditorium.

The PRS brought a professional "demonologist" to Old Botany in order to conduct some Electronic Voice Phenomena (EVP) testing -- primarily what the movie White Noise is based on.

"There's no way it could have been set up because we had 20 or 30 people in the room that were just random ... We checked his tape recorder as well," Buell said. "Every question that we asked, he would play the tape back and you'd hear a voice respond."

Topher Young (freshman-human development and family), director of general members for PRS, said the evidence was "resounding" as opposed to other buildings that they checked with EVP testing, like Schwab Auditorium.

"At the time, when we're asking the questions, we couldn't hear anything; it was complete silence," Young said. "But when you played it back there were definite words being said, sometimes on the verge of profanity."

Schwab Auditorium

Lore throughout the years has referred to the collective term for thespians' paranormal experiences at the Schwab Auditorium as encounters with "Schwabo the Ghost," said Bill Schwab, Penn State alumnus and former Penn State thespian.

"Any time you're down in that basement late at night, you know there's nobody else in the building," Schwab said.

"But you hear footsteps walking around upstairs or on stage, you hear footsteps coming from behind. There's a definite presence in there," he added.

Thespians throughout the years have reported a number of paranormal encounters in the auditorium, ranging from auditory presence to visible encounters with vanishing apparitions. "President Atherton is buried outside, and people have claimed to see someone dressed in clothes from that era, a figure like that walking around," Schwab said. "That's just one of the many ghost-type stories that come from that building."

The PRS, though, has found no strong evidence for paranormal activity there.

Using simple tools like audio recorders and video cameras, you can try your own paranormal investigation for these purportedly haunted buildings.

After all, it's only Halloween. What can you possibly be afraid of?