What was found
APPROX 20 MIN AT CRUISE, FL 360, APU FIRE LIGHT ILLUMINATED WITH TRI-TONE ALERT FIRE BELL. APU WAS NOT OPERATING. PULLED APU FIRE HANDLE & ROTATED. PER QRH, WAITED 30 SECS, TRI-TONE ALERT CAME BACK ON & FIRE HANDLE REMAINED ILLUMINATED. MANIPULATING WIRES ON BACK OF LIGHT CAUSES LIGHT TO GO ON AND OFF, SUSPECT BAD TERMINAL RINGS AND LIGHT ASSY. FOUND LOOSE RING TERMINAL AND JUMPER WIRE CRACKED, ALSO LIGHT ASSY. LOOKS DAMAGED. REPLACED BAD RING TERMINALS, REPAIRED JUMPER WIRE, AND REMOVED AND REPLACED LIGHT ASSY. PERFORMED OPS CHECK OF ENGINE / APU FIRE LOOPS ALL CHECKS GOOD AT THIS TIME. ALL ACCESS PANELS REINSTALLED.