Crews arriving just before 10:30 a.m. found flames coming from the second floor of a home in the 400 Block of Carmichael Drive, according to the Upper Gwynedd Fire Department.
A second alarm was issued, requesting aid from neighboring fire companies.
Power was cut to a number of homes in the area, local police said.
Authorities are urging residents to avoid the area as crews extinguish the fire. They were still on scene as of 12 p.m.
It was not immediately known if there were any injuries.
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