The fire was reported at 12:01 a.m. along the fence at the rear of the home at 1064 Clark St.
Arriving firefighters found the fire had spread to the garage, burning two walls and a portion of the roof and attic, fire officials said.
Firefighters had the blaze controlled within 10 minutes. Extensive overhaul was necessary to put out the fire, fire officials said.
The cause of the fire appears to be an electrical extension cord that was running under the fence and connected to a pump used to circulate water for a fish pond.
Damage to the fence and garage was estimated at $20,000, fire officials said.
No injuries were reported.