Wheeling firefighters responded to the fire shortly before 4 p.m. Wednesday.
Nobody was at the home when the fire broke out, according to the Rev. Fred Annie of the Roman Catholic Diocese of Wheeling-Charleston.
Schmitt, who was appointed bishop of the diocese in 1989, moved out of the house a few weeks ago so it could be renovated for his successor, the Rev. Michael Bransfield.
``This was a tragedy for us,'' Annie said. ``We were preparing for the new bishop to arrive. We wanted the house ready by Feb. 15.''
Annie said it was lucky that no one was in the home at the time of the fire. Some plumbing work had been done earlier Wednesday.
``Although there is some damage, nobody got hurt,'' he said.
Wheeling Fire Chief Steve Johnston said the cause appears to be accidental but the incident remains under investigation.
Johnston said the blaze appears to have originated in a second floor bathroom, causing extensive damage to the second and third floors and the roof of the structure.
``We're going to have to interview the workmen who were there,'' Johnston said, to determine how long the fire was burning before it was noticed.
The three-story house was built in 1905, and the diocese has owned the property since 1963.
Bransfield will be installed as bishop to lead the state's 76,000 Roman Catholics on Feb. 22.
