The multi-alarm fire broke out around 11:45 p.m. on the 3000 block of Delsea drive in Franklinville.
The large house was set in a wooded area. Tankers were called in from surrounding areas to help assist in putting out the fire.
It took firefighters over an hour to get the fire under control.
Russell Anderson, a member of the Franklinville Fire Company, sustained a sprained knee and received hospital treatment.
K-9 unit investigators detected accelerants inside the unoccupied house. The owner of the home is believed to be a township resident.
Police say any injury resulting from a deliberately-set fire upgrades the resulting charge to aggravated arson.
Also on the property is a separate building, which houses an auto body repair business. That building was not damaged.
The fire is being investigated by the Gloucester County Prosecutor's Office, the Gloucester County Fire Marshal, the New Jersey Fire Marshal and the Franklinville Police Department.