What was found
AIRCRAFT WAS GROUNDED: DESCENDING THROUGH 15,000 FT FLIGHT ATTENDANTS CALLED SMELLING BURNING ELECTRICAL, WE SMELLED IT IN COCKPIT AS WELL. SHUTOFF COMMERCIAL, GALLEY AND CABIN PUSH BUTTONS SMELL DISSIPATED AFTER SHUTTING OFF PUSH BUTTONS. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT LANDED AT MEM SAFELY WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND CIRCUIT BREAKER FOR AIR CONDITIONING RE-CIRCULATION FAN TRIPPED AND DETERMINED THE CAUSE OF THE ODOR WAS THE LEFT RE-CIRCULATION FAN AND REPLACED IT PER AMM 21-21-51. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.