The flames tore through the attic around 6 p.m. in the 300 block of Old Evans Road.
The family was at home at the time.
The homeowner said he went to turn the lights off and they wouldn't go off. He looked in the attic and there was fire everywhere.
He said the house was built in the 1930s and it has old cloth-covered wiring.
The fire marshal says an electrical problem is what sparked the fire.
No one was injured.