What was found
(CAN) DURING CLIMBOUT PASSENGER ALERTED FA TO SMOKE SMELL IN REAR OF CABIN , SMOKE WAS THEN VISIBLY OBSERVED BY PASSENGERS AND FA. FLIGHT RETURNED TO DEPARTURE AIRPORT AND ERS WAS REQUESTED. AIRCRAFT WAS APPROX. 2000 LBS OVERWEIGHT BUT LANDED AND TAXIED TO THE GATE WITHOUT FURTHER INCIDENT. MAINTENANCE DETERMINED THAT THE SIDEWALL LIGHTING ASSEMBLY AT SEAT 6F TO BE AT FAULT. RECEPTACLE FOR LIGHT APPEARED PITTED AND MAY HAVE CAUSED LIGHT ASSEMBLY TO SHORT OUT. LIGHT ASSEMBLY WAS REPLACED IAW AMM 05-51-01 PAGE 601 (TC NR 20070106001)