What was found
NR 2 FIRE LIGHT MALFUNCTIONED. APPROX 15 MINUTES INTO A NIGHT FLIGHT, A DIM, ALMOST BACKLIGHT GLOW CAME ON THE NR 2 FIRE WARNING LIGHT. FIRE LIGHT DID NOT ILLUMINATE. ALL OTHER ENGINE INSTRUMENTS WERE NORMAL AND NO WARNING LIGHTS ON THE ANNUNCIATOR PANEL. RETURNED TO BASE AND DURING SHUTDOWN THE DIM GLOW OF THE FIRE LIGHT WENT OUT WHEN I TURNED THE GENERATORS OFF. MX RESPONDED AND DISCOVERED THERE WAS A BAD CONTACT ON 1 OF THE 4 LAMPS INSIDE THE FIRE LIGHT. MX REPLACED THE BULB AND THE ACFT WAS PUT BACK INTO SERVICE.