Velma Kellen, 73, of Yelm said she called a repairman recently to determine why her new furnace wasn't heating her home and he came out of her house's crawlspace with unexpected news, KOMO-TV, Seattle, reported Wednesday.
"He says, 'Well, I've got good news and bad news. I've got your ducts fixed, but somebody's been living under your house,'" Kellen said.
"I was just amazed when he came in and told me," Kellen said. "I couldn't believe it. I thought, golly sakes."
She said the repairman discovered several empty beer cans and liquor bottles underneath the house.
"They cut the duct so that the warm air was blowing down on them," she said. "They were getting all my warm air from the front of the house."
Kellen said she suspects the intruder was the source of marijuana smoke she often detected in her home.
She said she does not know how long the mystery person was squatting beneath her floor.
Police were notified.