Fire officials say there were no witnesses to how an "intentionally set fire" broke out on Boynton Avenue on Dec. 20, and they are looking for information.

The fire started just after 6 p.m. Wareham Fire Department officials said no one was hurt, though the homeowner was inside the one-story ranch at 12 Boynton Ave. at the time.

"It was a very small fire," said Jennifer Mieth, spokeswoman for the Office of the State Fire Marshal, but added: "It doesn't really matter the size of the fire for us. What matters is somebody set a fire, because all fires start small."

The fire caused approximately $500 in damage to an exterior wall-covering at the home, according to the Wareham Fire Department.

Mieth said investigators are asking anyone who saw or heard anything around the time of the fire to call the statewide Arson Hotline at 1-800-682-9229.The hotline is part of the Arson Watch Reward Program, which provides rewards of up to $5,000 for information that helps to solve the crime.

Though there has been a string of intentionally set fires in Southeastern Massachusetts, Mieth said it is likely unrelated to this incident.

"There is absolutely nothing to lead the investigators to think that there is any connection whatsoever," Mieth said.

Firefighters were at the scene for about an hour and a half. A total of 15 firefighters, two fire engines, a ladder truck, and two other fire department vehicles responded.

The incident remains under investigation by Wareham Fire, Wareham Police, and the state Fire Marshal.