While crews were on the annual Santa run in Cove Point Calvert alerted units at 1922 hrs to Field Rd in White Sands for smoke coming from the roof. Both Engine 31 and Truck 3 promptly responded. EMS Captain 7 arrived on scene advising Calvert of a single story dwelling with smoke coming from the eves of the roof on the alpha side of the structure. Engine 71 arrived and opened the attic hatch finding light smoke conditions within the attic. Truck 3 was the first special server to arrive on the scene and assumed the first due special service responsibilities. The crew from Truck 3 utilized the thermal imager to to investigate where within the ceiling the smoke was being produced. After further investigation within the attic a overheated heating unit was found giving off the smoke conditions. Units from Company 7 and 3 worked together to exhaust smoke from the residence and secured the power. Units cleared the scene after 30 mins and resume the Santa Run.