What was found
ON TAKEOFF, AFTER RAISING THE GEAR HANDLE THE PRESS TO TEST & LIGHTS C/B (P6-3, LANDING GEAR) POPPED. 1ST & 2ND VERTI ROWS ON THE DOOR LIGHT PANEL LIGHT UP. ON RECOVERY, NONE OF THE GEAR LIGHTS WOULD LIGHT. M/GEAR EXT ACCOMP. F/O NOTICED A SPARK BEHIND 3 GRN LIGHTS WHEN HANDLE UP. DOOR PNL LIGHTS W/N PRESS TO TEST. T/S SYS PER WDM 33-18-01. USING F/O STATEMENT OF OBSERVING SPARK, PULLED M/G WARN MOD FROM PANEL, SET C/B, WITH PANEL REMOVED C/B DID NOT POP. DOOR LIGHT PNL DOES PRESS TO TEST. FOUND BULB CONTACT FOR N/G GRN LIGHT HAD COME IN CONTACT WITH BASE GROUND SHORTING OUT THE CIRCUIT. REMOVED AND REPLACED L/G WARNING MODULE PER 32-61-001-4. OPS CK'D PER 32-61-021-5 AND 32-62-011-5.