Walking down the narrow dimly lit hallway of the Biological Sciences Building after hours as you intend to lock up the premises, a sudden feeling of a presence builds behind you. You turn around to see a shadowy figure walking toward the bathroom, but the echo chamber-like hallway produces no footsteps.

Before you can tell the shady figure you’re locking up and that he needs to leave the building — he disappears.

This incident, which occurred on Friday night, Oct. 13 around 8 p.m., left police aide Alonso Saravia wary of what goes bump in the night on campus.

“There have been times that I’ve heard the voices of people coming from classrooms that are empty and locked,” Saravia said. “How does one explain that?”

Although there’s no solid evidence that ghosts exist, belief in the paranormal by Americans has soared in recent decades.

According to a survey conducted by Chapman University earlier this year, out of the seven paranormal phenomenon listed on the questionnaire, only 25.3 percent of Americans hold none of the seven beliefs.

This means that nearly three-fourths of Americans believe in some type of paranormal wonder.

In a study conducted by the Pew Research Center in 2009, nearly one in five or 18 percent of U.S. adults claim they’ve seen or have been in the presence of a ghost.

That same survey concluded that 29 percent of American adults said they felt in touch with someone who has died.

People, like custodians and police officers, who spend time at CCC while the campus is submerged into its eerie still silence, after night classes are excused, often share stories of spooky experiences they endure after the sun sinks below the horizon of the Marin Headlands.

Night shift custodian Jackie Allan-Smith said in the past she’s heard sounds like someone was saying her name in the older buildings on campus.

“My mother told me a long time ago, if I hear someone calling my name, but nobody is there — don’t answer.” Allan-Smith said. “I still won’t go in the building where they keep the cadavers.”

The unnerving feeling that he wasn’t alone made Saravia turn around and catch eye to a dark figure dressed in a suit and hat boasting a beard walking toward the building’s rest room.

“I felt like I wasn’t alone anymore, so I turned around. I could clearly see what the man was wearing and could tell he had a long beard,” Saravia said. “But once I approached the bathroom and called for him to come out I realized that there was no one there.”

Saravia said the automated lights in the men’s rest room were triggered on before he entered the door. However, as he investigated he found the bathroom completely empty.

He said what made his heart stop and his hair raise was when he checked the women’s room it was pitch black as expected, unlike the men’s room.

“Someone or something triggered the automated lights in there,” he said. “It gave me the chills.”

Late shift campus custodians commonly recall feeling unseen presences and hearing voices while cleaning the interior of the buildings. A few consider certain areas of buildings personally off limits and won’t come close to them after hours because of encounters they’ve witnessed in past experiences.

Contra Costa College Building and Grounds Manager Bruce King recounted hearing from Police Services about inexplicable security footage from the General Education Building. The footage, which had a timestamp around 3 a.m., showed the locked sliding doors blow outwardly open by a tremendously powerful unseen force.

The force was so powerful the heavy black doormat laying at the foot of the sliding door was also blown back several feet.

The unexplained phenomenon was first thought to be the violent release of built-up pressure from the building’s ventilation system. However, King said that theory is impossible because the ventilation system is on a programmed schedule which doesn’t turn on until 6 a.m.

“This happened at least twice since the building has been up (August 2016),” King said. “My jaw hit the floor when I heard about it.”

Rumor has it that the campus is built on ancient Native American  burials grounds, however no one on campus could confirm or deny that fact.