One of the Duluth Paranormal Society's first cases was an investigation at a private residence where a 3-year-old girl was seemingly having conversations and playing games with an unseen someone named "Earl."

During two investigations at the house, the group captured recordings of disembodied voices saying things like "hello" or "peek-a-boo."

The team's conclusion: They weren't picking up bird sounds or the voices of the owner's other children. There was something inexplicable going on - and that something was making noises, moving objects and interacting with the little girl. Paranormal activity? There was no reason not to think so, according to lead investigator Amanda Paszak.

That's true of about 85 percent of the 10-or-so homes the Duluth Paranormal Society is asked to review each year, she said. Frankly, Paszak prefers when the group can find a reason for the bumps, footsteps and voices.

"We're not afraid to tell people it's nothing," she said. "We'd rather prove something is not haunted. We'd rather be able to explain it."

While local paranormal experts often spend time sweeping through local landmarks, like the William A. Irvin or the Duluth Depot, some are called on by homeowners who make claims about unusual and seemingly inexplicable activities within a private residence. These sessions, conducted in the dark, include the tools of the trade, interviews with family members and, oftentimes, research into home's history.

Verdict: Faulty furnace

A door slams closed on its own. There is a rattling noise from within the structure of the home. An icy draft, a flickering light, an occupant develops a general feeling of unwellness. There are plenty of reasons to suspect a house is haunted.

But in some cases, the answer is more normal that paranormal.

Justin Holley of the Minnesota Paranormal Study Group, which operates on the Iron Range, said - like Paszak - he likes to be able to tell a client that it's the ice machine banging, the furnace needs repair or the electrical wiring needs some work.

"We take pride in being able to debunk stuff and put minds at ease," he said.

Other explanations include: Bad water pressure, loose pipes, air pressure in a home that causes a door to close downstairs when one opens upstairs.

Holley said his group gets calls to investigate from three different kinds of clients: nonbelievers who are humoring family members; people who believe in the paranormal and want to share what they are experiencing; homeowners who have been forced to believe based upon what's happening in their home.

Debunking isn't always possible.

Holley's group investigated a home where the meter that records electrical and magnetic forces would blink whenever a team member touched a Bible. They've heard footsteps and voices. At one home, an entity was throwing change around the house. Whenever they walked into a new room, there would be scattered coins on the floor.

"We never found an explanation for it," Holley said.

'The holy grail of paranormal activity'

The first tip regional professional investigators offer up to homeowners who suspect paranormal activity: Call us.

The investigators cite personal experiences that have left them forever changed and forever chasing more.

Holley, of Bemidji, saw a full-body apparition when he was 12. He and his cousins - who also saw it - were waiting in the car for his mother, who was inside a house visiting a friend. A figure looked out a picture window toward the yard, then he became less solid, faded to tendrils and disappeared.

"I thought it was a person and they vanished right before my eyes," he said. "After further investigation, it was the husband of a friend of the family who had died a month earlier."

It was Holley's first full-body apparition, but it wasn't his last.

"It's exhilarating," he said. "When you've done this for a while, you almost know when something is going to manifest. there's an (electromagnetic field) burst."

Paszak, of Proctor, was 11 when a faceless man wearing her father's pajamas came into her bedroom on three consecutive nights.

"I found it odd that it didn't scare me," she said. "It was intriguing."

She lives in that same house, but has not seen anything like it - or during investigations - which, in addition to private homes, has included visits to the William A. Irvin.

"It's the holy grail of paranormal activity," she said of spotting a ghostly figure. "We've had sounds. We've never seen anything move when it shouldn't - it's not as Hollywood. It's just sounds and voices and things (we) can't explain."

Mike Gams, lead investigator of Iron Range Paranormal Research, has always had a connection to spirits - including Chris, a mischievous spirit at his grandparents' home in Virginia. Gams' group spends time in cemeteries and a few years ago he was followed back to his Biwabik home by Rachel, a full body-apparition wearing a 1940s trench coat. This wasn't a friendly spirit, and Rachel's presence had an adverse effect on what was a normally a bicker-free relationship between Gams and his wife.

"I had her stuck in my house for two weeks," Gams said. "It almost cost me my marriage."

Finally, they were able to give her a ride back to the cemetery, and order was restored.

Wanted: One radio

Before you bring in the professionals, Gams said, there are plenty of inexpensive ways for amateurs to conduct an investigation using common household supplies.

Step one: a radio. Set it to a nonstation with static, hit record, walk away.

"If there is anything in your house, you (will) hear them over the white noise," Gams said. "You can hear if they're male or female or if they're moving something in their world."

Try an old-school technique: The earliest of ghost hunters sprinkled white powder, like flour, across the floor before leaving the house.

"If you come back and see footprints, you know you have spirits," Gams said.

It is also possible to use an EMF meter to detect spikes in the electromagnetic fields or unattended video cameras to capture orbs.

If you're seeing evidence, give the investigators a call.

'Let it be'

Paszak has found that most homeowners who contact the group aren't looking to necessarily get rid of spirits. Clients just want to understand what's going on.

"If we can provide proof that they're not crazy, that's our goal," she said.

If it isn't causing adverse effects on your life, maybe consider ignoring it.

"Let it be," said Holley. "Don't communicate with it. People are curious. They don't want paranormal activity, but when they experience it, they pursue it. Then they have more."

But if you are spooked out by what seems to be paranormal activity, ridding a house of spirits can be relatively easy. You're likely dealing with spirits that were once people, too.

"Take control of your home," said Holley. "It belongs to you. Have that conversation with any entity that might be in your home. 'This is our place, you're scaring us. We're not comfortable. You have to leave. (Or) you can stay, but you have to tone it down.'

"Nine out of 10 times, that takes care of it."

If it doesn't work and/or the spirit seems evil, the investigators suggest seeking council from a Catholic priest.

Gams, meanwhile, takes a proactive approach to keeping the bad at bay:

"I sage my house quite often," he said.

• Minnesota Paranormal Study Group: minnesotaghosts.com

• Iron Range Paranormal Research: facebook.com/ironrangeparanormalresearch

• Duluth Paranormal Society: duluthparanormal.com