What was found
BOS - FLT 4622 - CREW REPORTED SMOKE COMING UP FROM FLOOR ON THE FIRST OFFICERS SIDE WITH A STRONG ODOR OF BURNING ELECTRICAL INSULATION. MAINTENANCE COULD NOT DUPLICATE DISCREPANCY. AIRCRAFT WIRING AND ELECTRICAL BOXES WERE INSPECTED UNDER FLOOR, SIDE WALL, AND INSTRUMENT PANEL WITH NO DEFECTS NOTED. AIRCRAFT WAS RELEASED FOR A FUNCTIONAL CHECK FLIGHT. FCF WAS SATISFACTORY AND AIRCRAFT WAS THEN RETURNED TO SERVICE. (M)