PHOENIX -- Investigators believe an electrical issue sparked an early morning fire at a Phoenix home Wednesday.
It happened in the neighborhood northwest of 41st Avenue and McDowell Road. Eight crews responded at about 5:30 a.m.
The homeowner was not home when the fire started because the house is undergoing renovations.
While they have not pinpointed the cause yet, investigators said it looks like there might have been a problem with the wiring in the attic.
Because it was a "very active fire" with quite a bit of heavy smoke and flames, crews quickly went defensive.
Firefighters limited the damage to the inside of the home. The external structure is still sound.
No injuries were reported.
A man who lives in the area told 3TV's Heidi Goitia there have been similar incidents at other homes in the neighborhood. He believes old aluminum wiring connected to outlets, switches and other wires in junction boxes is to blame.
"A national survey conducted by Franklin Research Institute for CPSC showed that homes built before 1972, and wired with aluminum, are 55 times more likely to have one or more wire connections at outlets reach 'Fire Hazard Conditions' than homes wired with copper," reads a publication by the Consumer Product Safety Commission on repairing aluminum wiring.
The problem is deterioration, and there are not many warning signs
"Aluminum-wired connections and splices have been reported to fail and overheat without and prior indications of problems," according to CPSC.