Oshkosh police report one of the two men wounded in an exchange of gunfire Sunday night has died. A 25-year-old Oshkosh man was treated for a wound and released, but an 18-year-old Appleton man died from his injuries.  Neither man has been identified.  Police were called and told about an exchange of gunfire at a home at about 9:00 p-m.  They say they are looking for another suspect who was involved, a black man in his late teens or early 20s who may be armed.  Broadcast reports identify a neighbor as saying the 25-year-old man knocked on her door, telling her two men had thrown a brick through his window and entered his home carrying guns.