One day back in the early 1990s, Gerry Pearle went out looking for beach plums around Onset to make jelly for a cooking class she taught. But as she searched for plums, Gerry found something else.

Gerry, of Marion, stumbled upon the On-I-Set Wigwam, built by Spiritualists who flocked to Onset in the 1870s to settle and practice their religion. The wigwam, an oddly-shaped, eight-sided, meeting hut modeled after the Native American wigwam, was and is used to perform healings and to hold readings and other Spiritualist ceremonies.

Back then Gerry didn’t know much about the Spiritualists or their history in Onset. But once she learned of the building, she and her husband Paul became devotees of it, helping to renovate it and raise awareness of its purpose and history.

Gerry and Paul now live in Marion after more than 40 years living on Great Neck Road. For their efforts, Gerry and Paul were given the Massachusetts Historical Society’s Preservation Award.

On Sept. 21, Gerry will be the guest speaker at the wigwam, and helping to spread word about why it’s there and what it’s all about.

“She knows so much about that wigwam,” said Patti Craig, president of On-I-Set Wigwam Co-Workers Spiritualist Camp. Craig recalled that when she showed interest in becoming the group’s president, she was told she had to speak with Gerry first. “Anything about the wigwam, you go to Gerry Pearle for it. That’s why we’re doing this thing Sunday—so it’s not lost.”

And lost is what the wigwam may have been without the Pearles.

When she found it, Gerry recalls, “It was falling into the ground. It was really in bad repair,” said Gerry.

A member of the first Wareham Historical Commission, at the time, Gerry thought she’d find someone who knew what the building was all about.

“Not one person knew a thing about this building,” she said. “It made me even more curious and I had to find out.”

She said she found several books, including one written by Russ Gildman of Whitman called “The Story of the Wigwam,” which was written in 1904.

“That was like a bible,” she said. “It explained everything they did, what they did, and how they did it.”

Fittingly, in the 1894 structure’s 100th year, the Pearles and others were able to raise the funds to fix up the building, and Paul oversaw the eventual renovation.

But it didn’t end there—since then, Gerry and Paul have continued to learn and spread the word of the building, and though Paul is no longer able to do so due to health reasons, Gerry is still at it at 86 years old.

A Catholic, Pearle quickly took an interest in the Spiritualists. She said they had a deep connection with the Native Americans, which is evident by the Native American decor throughout the building, as well as the design of it.

“Every religion of every of philosophy has something of interest that you should know about,” said Gerry. “I wanted to know about the Spiritualists. When I did, I found out that they believe that this life that we’re living is a preparation for the real life—a life of eternity. Their only rule was the Golden Rule—to do unto others as you would have them do unto you. And they believed the spirits of the people that were gone never left completely.”

“She’s awesome,” said Craig of Gerry.

Craig, who lives in Brockton, said when she first phoned Gerry the two talked for four hours long.

“She told me that she could tell by the sound of my voice that I cared about it,” said Craig.

Currently, the wigwam, which Gerry said is the only building of its kind in the world, is open from May to October, with several different weekly events taking place. There’s a two-day fair, and on Thursdays a different medium comes to give everyone “a smidgen of a message,” according to Craig.

“It’s pretty busy,” said Craig.

Gerry said the wigwam was the first building in Massachusetts to be nominated for the National Register of Historic Places, which recognizes buildings worthy of preservation.

“There are so few people who know about this,” said Gerry, noting that she’d be taking questions at her presentation. “A town is defined by its buildings. Everything just came together [concerning the renovation]. It was really unbelievable. It’s something I feel proud of.”

On Sunday, Sept. 21, Gerry Pearl will present The History of the Wigwam at the On-I-Set Wigwam, located at 9 Crescent Place at noon. The presentation will follow the Sunday service, which takes place from 10 a.m. to noon.

There will be readings and healings at the service. The public is welcomed to attend. A donation is requested. For more information, visit onisetwigwam.com.