What was found
BWI - MAINTENANCE REPORTED THE FLIGHT DECK EMERGENCY EXIT LIGHT INOP. MAINTENANCE RELAMPED LIGHT WITH NO HELP. REQUIRES FURTHER TROUBLESHOOTING. PLACED ON MEL 33-15, C/N 2907C09. AIRCRAFT RESTRICTED TO DAYLIGHT OPERATION ONLY. MAINTENANCE IN PHL, FOUND THE GROUND WIRE DISCONNECTED AT GROUNDING POINT. RECONNECTED GROUND WIRE AS REQUIRED. OPERATIONAL CHECK GOOD. REMOVED MEL.