GORHAM — Jim O’Connell, a Connecticut screenwriter and producer of “Terrestrial Extras,” a film based on his experiences as an alien abductee, set the stage at the Experiencers Speak conference Saturday.

O’Connell told the audience to be on the lookout for an extraterrestrial being who poses as a red-haired woman who communicates telepathically. The woman, O’Connell warned, has been known to stalk him at conferences where the subject focuses on close encounters with non-earthlings.

“They seem to be following me,” said O’Connell.

Suitably spooked, the audience at 25 School St. settled in for 12 hours of talks by a dozen speakers, many of whom say they had been abducted by beings from another planet or conduct UFO research.

The conference was organized by sisters, Audrey and Debbie “Starborn” Hewins of Mechanic Falls. The twins, 39, started a national support group for abductees, Starborn Support, after what they describe as a lifelong series of encounters with extraterrestrials.

“We decided to get people together,” said Audrey Hewins.

By early afternoon the expo had drawn about 70 people, who paid $25 at the door to get in. They were split between those who claimed to be fellow abductees and those who said they wished to be abducted. A dozen booth operators peddled books written by the speakers, sold inflatable alien dolls and dispensed psychic readings and chair massages.

At noon, the group broke for a lobster roll luncheon.

Among the headline speakers was Travis Walton, a logger and author of “Fire in the Sky,” who said he was kidnapped by space aliens in the Arizona woods in 1975 and held captive for days.

Other big names included Kathy Marden of Florida, who wrote a book based on the lives of her aunt and uncle, Betty and Barney Hill, a Portsmouth, N.H., couple whose story about a 1961 alien abduction in northern New Hampshire and its aftermath gained national attention in the 1960s.

Anne Channing, a Portland clinical social worker, said people who say they have been abducted by aliens or had other extraordinary experiences feel isolated from the rest of the world. She said she doesn’t know whether alien abductions are real, imagined or a hoax.

“But I believe what people tell me. What they say has all the earmarks of a true experience,” Channing said.

Some of those attending the expo said their encounters with alien beings were life-altering.

Kevin O’Brien, 30, of Bar Harbor, came to the expo hoping to meet other Mainers who had experiences like his. A stay-at-home father, O’Brien said his first encounter occurred three years ago during a 2 a.m. walk from his brother’s home in Bangor.

He said he has had encounters with tall human-like creatures he calls the wizard people who are sending a spiritual message to earthlings.

“They are saying, ‘Be happy and as loving as possible.’ This is the message I am getting,” said O’Brien.

Tom Kennedy, 51, of Old Orchard Beach, said he has had a series of coincidences and odd experiences stretching back decades. He said he has seen strange orb-shaped objects in the clouds above Scarborough and Saco.

“I think it is the biggest thing since sliced bread,” Kennedy said.