The Kenosha Fire Department is continuing to talk to neighbors as they investigate the cause of an early morning fire in an unoccupied home at  55th Street and 16th Avenue in Kenosha.   The fire was reported at 5 AM.  According to officials, the fire began on the exterior of the two-story building on a side that faces an alley.  The fire then extended into the building.   Firefighters were on the scene for about three hours.   There were no injuries from the fire.   Damage to the vacant house is estimated at between 15- and 20-thousand dollars.