Police and officials from the Provincial Electricity Authorities (PEA) raided the house in Ratchaburi town on Friday.
"We found bitcoin mining rigs, pointing to people using this house to operate a mine and using power they didn't fully pay for," said Jamnong Chanwong, a chief district security officer, AFP reported.
He told AFP records showed that electricity consumption in the house was large, but they had paid for very little of it.
Mining virtual currencies such as bitcoin requires powerful computers that consume huge amounts of electricity.
Bitcoin miners are considered manufacturers in Thailand and must pay associated taxes, but illegal mining has been on the rise for years.
Jamnong said his team tried to enter the house on Thursday but a guard denied them entry. They then returned with a search warrant and found most of the equipment had been moved.
He said the house had been rented by a company for around four months, but the power outages began mid-July when the mine likely became fully operational.
No one was arrested during the raid, he added.
It was the fourth time this year that authorities have raided an illegal bitcoin mine in Ratchaburi province.