A family of four was displaced from their west Petaluma bungalow after faulty wiring sparked a fire Saturday morning.

The 6:58 a.m. blaze in the West Street home ignited in the master bedroom wall before spreading to the attic, Petaluma Fire Department Battalion Chief Jeff Holden said.

About 20 personnel from Petaluma and Rancho Adobe Fire Protection District put out the blaze in about an hour, Holden said. Crews had to remove the ceiling in two rooms to douse the insulation, he said.

Damage to the rented home and its contents was estimated at about $25,000, Holden said. The home was built in the 1930s or 1940s, and the old electrical knob-and-tube wiring caused the blaze, Holden said.

The fire didn’t threaten any nearby homes or prompt evacuations, he said.

The parents, their two young children and pet birds escaped without injury. They planned to stay with family in Marin County, Holden said.

You can reach Staff Writer Hannah Beausang at 707-521-5214 or hannah.beausang@pressdemocrat.com. On Twitter @hannahbeausang.