The two-alarm fire, discovered by a neighbor, began in the interior (rear of home), the State Fire Marshal's office reported.
The home was originally constructed in 1900. Significant renovations were in progress at the time of the fire.
Anyone with information is urged to contact the Northwest Regional Office at 410-996-2793 or the Arson Hotline at 1-800-492-7529.
Crews on scene reported that the home was fully involved when they arrived.
Firefighters from Rising Sun, Perryville, North East, Elkton, Water Witch of Port Deposit, Darlington, Level, Union of Oxford, Robert Fulton, and West Grove worked at the scene.
Deputy State Fire Marshal Howard Ewing, Delmarva Power, and a county building inspector were also called to the home.
The fire was brought under control at 6:35 a.m.