What was found
OVERHEAD EMERGENCY LIGHT INOPERABLE AT ROW 18. CORRECTIVE ACTION: SWAPPED LIGHT WITH KNOWN GOOD LIGHT, NO HELP, REF A321 AMM 33-51. SUSPECT POWER SUPPLY STK 34-3351-9-0001 PLACING ITEM ON MEL 33 -50-02D. FOUND LITE PLUGGED IN BACKWARDS. SWAPPED CONNECTORS ON LIGHT ASSEMBLY, OPERATIONS GOOD. MEL AND PLACARDS REMOVED.