OKLAHOMA CITY - The Department of Corrections building has a history, not known to many Oklahomans.

As Halloween approaches, staff and guards share their accounts of ghosts that roam the halls. They say they appear in dark shadows, and so far have not been caught on camera.

“I thought I was going crazy, maybe my eyes are playing tricks on me. But again, when the same things happen to other people and it keeps reoccurring every few months… you learn to live with it,” said Lieutenant. Justin Tate, a guard at the prison.

D.O.C sits off North Martin Luther King Avenue, and was built back in 1917.

Historians tell News 9 that the building was first created as a retirement home, nursing home, and a hospital for civil war veterans.

It was originally named “The Oklahoma Union Soldiers Home.”

Those with the Oklahoma City Metropolitan Library System said it’s likely many veterans lived and died in that building.

In fact, the “Union Soldiers Cemetery” is less than a mile away atop a nearby hill.

“I would except there are things that I don't understand, or I don't have the answers to,” said Matt Elliott, a spokesman for D.O.C. “We have a lot of people who say they have seen a lot of different things.”

Staff have reported doors opening on their own, the men’s bathroom faucet coming on by itself, and even hearing phantom footsteps in the upper floors of the building.

A guard has even reported chasing a ghostly figure down the hallway, after he believed an intruder had broken into the D.O.C building.

Each time staff reviewed surveillance footage, but said they found no human activity.

They believe paranormal activity is the source of these tricks-and-treats.

While some people have been scared, workers say no one has every been hurt in these encounters.

“One time, I heard someone running down the hall upstairs. But, when I went to go check, there was no one else on the premises,” said Kimberley Owen, another employee of D.O.C.

There is one questions looming on everyone's mind.

Who will visit this Halloween?