Halloween falls on a school night this year, so the local spirits may not be out in full force on Monday, but there are plenty of opportunities in southeastern Connecticut this weekend for the local ghouls, ghosts and goblins to get out and do some spooking.

The Salem Historical Society is starting the weekend’s festivities Thursday night with a free lecture on the vampire folklore of Connecticut.

The lecture by state archaeologist emeritus Dr. Nick Bellantoni is just one of many activities in honor of Halloween this weekend. Other towns and organizations will be hosting performances, Halloween parties and trick-or-treating to give everyone an opportunity to show off their best costumes.

Bellantoni served as the first official state archaeologist for 27 years, and he said he has worked with the Salem Historical Society multiple times because the town had a strong Native American presence for thousands of years and many Colonial properties. However, the investigation that inspired his vampire folklore presentation took place in Griswold in 1990.

Two boys found human skulls while playing in a gravel bank, and investigations found a Colonial graveyard in the area that dated back to about 1757. While Bellantoni was working to relocate the other graves in the burial ground — about 30 in all — he found a stone-lined crypt where the bones of the body inside were rearranged.

In a phone interview, he explained that tuberculosis outbreaks were common in Colonial times, and people believed that those who died of the disease came back to life to spread it to others. To prevent this, the bones of the bodies were rearranged in their caskets to put the undead to rest. In the Griswold crypt, the femurs were crossed, the ribcage was crushed, and the skull was removed.

Other researchers had found historical accounts of people trying to stop these “vampires,” but the tuberculosis lesions found on the bones of the Griswold body were the first physical proof that people followed the folk medicine belief.

“You never know where archaeology is going to take you,” he said.

Bellantoni’s lecture, which takes place at 7 p.m. Thursday at the historical society building on the town green on Route 85, is just one of many Halloween activities this weekend.

In Norwich, guests are encouraged to dress up in their creepiest costumes for Christ Church School of the Arts’ showing of “Phantom of the Opera” at 7:30 p.m. Friday. Organist Robert Humphreville will be playing along with Lon Chaney’s 1925 classic silent film as part of the school’s seventh annual silent film showing.

Admission is free with a suggested $5 donation, and concessions will be available. The school is located at 78 Washington St. in Norwich.

Several towns, including Ledyard, Salem and the City of Groton, are hosting “Trick or Trunk” events Friday night. Residents get together to decorate their car trunks and hand out candy in a safe place. Times and registration fees vary, so call the local parks and recreation department for more information.

In New London, Hygienic Art will be holding its annual Howling Halloween Bash at 8 p.m. Saturday for adults 21 and older. The galleries will become the House of Horror, and artists from Spark Makerspace will be transforming the Hygienic Art Park into the Planet of Pus, a gruesome extraterrestrial world of intergalactic goo. There will be live music, a costume contest and food trucks. Admission for the event is $10.

Over the state line in Westerly, the Westminster Youth String Ensemble is performing its 16th annual Halloween concert at 2 p.m. Sunday. Arrive early for mask-making and stay for a costume parade and performances by Big Nazo Puppet Creatures. Guests are asked to bring a canned good to donate to the Pawcatuck Neighborhood Center.

To wrap up the holiday, Olde Mistick Village will be holding trick-or-treating starting at 4 p.m. Dozens of shops will offer treats for visitors in costume. Attendees also can vote on which stores have the spookiest shopkeepers.

For more Halloween activities, visit the Halloween calendar in the Oct. 27 edition of your local Times paper.

a.hutchinson@theday.com