Faulty electrical wiring sparked a fire in a Petaluma Victorian home Thursday night, displacing two families, said Petaluma fire officials.

A neighbor arriving home on Wilson Street spotted the fire at about 8:20 p.m. and evacuated people from the large two-story home, which was being used as two apartments.

Firefighters arrived three minutes later and found smoke coming through an outside wall and a resident using a garden hose on the building, said acting fire Capt. Chad Costa.

The fire was contained to a wall where it started. Damage was minimal but residents were told they couldn't stay because of the wiring issue, said Costa.

He praised the quick work of the neighbor for helping firefighter get to the scene while the problem still was small.

He estimated damage at about $1,000.