Fire crews were called to a home in the 10200 block of 34th Avenue SW just before 8:30 p.m. on Tuesday.
Firefighters originally battled the blaze from a distance after learning there may be ammunition inside. Crews were eventually able to extinguish the fire, but not before it did significant damage to the structure.
A man who lived at the home told fire officials he was trying to kill a spider in his laundry room using a can of spray paint and a lighter when the wall caught fire, according to Kyle Moore with the Seattle Fire Department. The man wasn't able to put the fire out himself, and he left the home when it began to spread.
"I don't want to encourage people to do this, but that's what he did," Moore said. "The spider tried to get into the wall. He sprayed flames on the wall, lit the wall on fire, and that extended up to the ceiling."
The man initially tried to put water on the fire, but he wasn't able to put it out and the blaze spread quickly spread into the attic.
"There are safer, more effective ways to kill a spider than using fire," Moore said. "Fire is not the method to use to kill a spider."
The building, which is a rental home, will cost roughly $40,000 to repair, Moore said. It will cost another $20,000 to repair or replace the contents of the home.
As for the spider, Moore said: "I'm pretty sure the spider did not survive this fire. The whole wall went."
The Red Cross is finding temporary housing for the man and a woman who lived with him.