The residents of the Columbus house -- where 10 students live on the second and third floors under one lease and five others live on the first floor under another -- said they thought the locked door in the basement led to a utility closet, but maintenance workers knocked the door down and found a bedroom with framed pictures and school textbooks, The Lantern, Ohio State's student newspaper, reported Wednesday.
The students had the locks changed and posted a notice for the basement dweller to call them.
They were soon contacted by a man named Jeremy who they allowed to collect his belongings.
"He was a nice enough guy," resident Brett Mugglin said. "He just wasn't supposed to be there."
Mugglin said he had encountered the man during the summer and thought he was a resident of the first floor.
The students said their leasing company, NorthSteppe Realty, changed the locks, but has done little else to compensate them.
Resident Jimmy Alderman said the company told him officials are waiting for the residents to propose a settlement for damages.
"It was a dangerous situation," Alderman said. "It could definitely have been a lot worse."