MIDDLESEX TWP — A bathroom ceiling fan may have sparked a fire Monday evening that caused minor damage to a vacant home in the township, authorities said. Two construction workers plastering in the ranch-style house on Park Drive reportedly heard a “popping” noise coming from the ceiling shortly before 7 p.m., said Chief Dave Metz of the Middlesex Township Volunteer Fire Company. “They smelled something burning in one bathroom,” Metz said of the workers. The house, which is about two-tenths of a mile north of Overbrook Road, is believed to be in foreclosure, officials said, and there was no one living there. According to the real estate website Zillow, the 2,263-square-foot home is listed for sale. “That bathroom had the smell of wood or lumber burning when I got there,” Metz said, “and there was a dark haze of smoke.” Firefighters pulled down the bathroom ceiling to get to the fire. A hand line connected to an engine was used to quickly douse the fire, Metz said. A damage estimate was not immediately available. The township firefighters were assisted by firefighters from Penn Township in Butler County and Richland and West Deer townships in Allegheny County. Middlesex firefighters were back at their station about 9:30 p.m.