A family has been displaced by a fire in their Monroe home.  Volunteer fire companies responded to upper Hattertown Road shortly before noon yesterday to find heavy fire showing on the first floor.  Crews made an aggressive interior attack, fighting fire on the first and second floors and in the attic that continued to flare up.  The original part of the home was balloon frame construction dating to the Civil War era.  Inside the home, there was an unusual layout and black-out smoke conditions.  A lack of nearby hydrants, and ice also made a challenging situation.  Trumbull and Easton firefighters also responded and several tanker trucks from Newtown supplied water. No residents or firefighters were injured during the 4 hour operation. The cause is undetermined and remains under investigation by the Monroe Fire Marshal. The residents will be staying with family.