Outside an abandoned, purportedly haunted former mental hospital in Anoka, Brandon Kuehn spotted something unusual.

Atop one of the boarded-up old brick cottages in this rundown complex, a ratty old curtain fluttered in a window. It was a bone-chilling overcast day, and the movement in the window was as apropos as it was unnerving. Kuehn walked straight toward it, as if called to the creepiness.

Kuehn makes it his business to notice the rustle of fabric when there should be none, to hear a faint voice on an airwave, to make out a blurry shape in the background of a photograph. Such otherworldly encounters are the basis for his art.

In paintings and installations, Kuehn chronicles paranormal activity in Minnesota. Traveling around the state to sites of legend and lore, he culls inspiration from the sinking of the Edmund Fitzgerald on Lake Superior, from tales of a haunted train trestle in the Minnesota River Valley, and from eyewitness accounts of Sasquatch footprints on a rural road in the North Woods.

His depictions aren't literal. They can't be. Kuehn has never seen a ghost.

What he portrays are the stories of others, having never seen evidence of a haunting with his own two eyes.

"I've heard that with different people, you're either sensitive or you're not, like you're tall or you're not; you're redheaded or you're not," Kuehn said. "I haven't been able to fake it."

Instead, he captures the mood he finds at these places. His works exude an eerie drama that, much like any paranormal sighting, leaves interpretation to the eye of the beholder. A white light around a figure, an oddly arranged pile of rocks, a lens flare captured in a photograph — all become the focal points in his paintings and sculptures.

Other pieces utilize ghost-hunting equipment: a field of laser beams that would dim if an invisible figure passed through it, a radio that incessantly sweeps through airwaves searching for the conversations with the other side. Those audio and visual contraptions were on display at a recent exhibition of his work at the Soap Factory in Minneapolis.

But Kuehn has never seen those laser lights flicker. He's never caught a voice on the radio that shouldn't have been there.

And the flutter in the mental hospital building?

"It's just drapes in an open window," he said as he got closer, sounding slightly deflated.

An appetite for haunted art

Kuehn, 40, was always fascinated by tales of ghosts, starting with one very big one, the Holy Ghost, he said.

He grew up in western Wisconsin, where he was a Catholic altar boy. "I got really into the candles and incense and the more mystical parts of a mass," he said. He also read a lot about Bigfoot and UFOs, and liked the idea that neither had been disproved.

As he struggled with depression later in life, that notion would soothe him.

"It's very comforting for me to know that there's more than this," he said. "It's what I was taught as a kid in the Catholic Church. There's all this stuff. We just have to wait and be patient."

Kuehn studied art at the University of Minnesota and earned an MFA at the Art Institute of Boston at Lesley University. His landscapes were inspired by the "uncanny," Sigmund Freud's concept of a sense of an otherworldly power, which, in a painting, could make the viewer question what he is seeing.

In 2014, Kuehn helped curate a group art show at Banfill-Locke, a Fridley gallery alleged to be haunted. He put out a call for art inspired by paranormal encounters, such as sketches of UFO sightings and sculptures of Bigfoot. There were entries from 30 states and three countries, and Kuehn was emboldened to discover there was an appetite for paranormal art.

"Up until then, if I had a big landscape, I might hide a sasquatch," he said. Now, he would put monsters front and center.

Kuehn received a 2015 Minnesota State Arts Board grant to develop a body of work that documents the state's paranormal activity. He used it to go "legend-tripping" in search of the unexplained, bringing along his ghost-hunting equipment and an open mind.

"He's like a method actor," said Chad Lewis, an author of dozens of books on the supernatural, including a volume on Pepie, the famous lake monster of the Mississippi River's Lake Pepin. "He tried to learn the paranormal, and really dived into his part for this."

Kuehn's explorations took him to Split Rock Lighthouse on Lake Superior, where he learned about the rogue "sister" waves that may have had something to do with the famed Edmund Fitzgerald shipwreck. He translated that story into paintings of three mega waves, overlaid with the freighter, split in two.

And it took him to Le Sueur, where a floating red light is said to appear along the railroad tracks, supposedly belonging to a hermit who died in nearby brewery caves. Kuehn represented the "spook light" with a sculpture of rocks from the site, lit with a red bulb.

In his studio in Anoka, a city known as "Halloween Capital of the World," Kuehn has a color-coded map with the sites he's traveled to and those he has yet to visit: "Mothman," "Wil-o-wisp," "Phantom cats."

"You can just go down the rabbit hole," he said.

In the decade that Kuehn's wife, Juli Schmidt, has known him, she's watched his interest in the paranormal evolve from a reader of Bigfoot comics to an all-out researcher into the supernatural.

While she considers herself a fan of his work, she doesn't want to know too much about what he finds.

"I can't even watch scary movies," Schmidt said. "I love his work, but the really spooky stories, I will not listen to."

The couple made a deal that Kuehn won't actively go looking for malevolent spirits, on the off chance that he might bring one home with him.

"He promised he won't seek that kind of energy," Schmidt said.

Scary storytelling tradition

Minnesota seems to have an abundance of haunted locations, which Lewis chalks up to a strong local storytelling tradition. When he wrote a book on the state's hauntings more than a decade ago, he chose from 400 ghost stories, not including sea monsters, woodland creatures and alien sightings.

"You literally could investigate haunted stories every single day and never run out till the end of the time," he said, "because many of these stories are not in stone. They're progressing, morphing, moving."

Most of the people drawn to the paranormal chase never actually spot anything out of the ordinary, Lewis said.

"But there's always that moment for me, like, 'What if something happens this time?' " Lewis said. "I always equate it to a gambler thinking he's going to win the jackpot this time. There's that excitement."

The excitement fuels Kuehn's artistic endeavors. Though he still craves proof that something exists beyond the confines of this world, he's not tempting fate.

Poking around at the asylum, he came upon an entrance to one of a network of tunnels connecting the cottages. During the first half of the 20th century, the tunnels were used to transfer deceased patients to the cemetery. They're ground zero for haunted sightings.

Kuehn walked to a stone stairway that led down to a battered wooden door, its screens ripping away from the frame, its rusty handle enticingly intact. The door was slightly ajar.

Kuehn gazed at the door for a moment. "I'm not going down there," he said.

He took a photograph, and walked away.