What was found
LEVEL AT 35000 WE WERE CLEARED TO 24000, AS WE STARTED DOWN FLIGHT ATTENDANTS ASKS TO WARM UP THE AFT SECTION, WE INCREASED LT PACK & STARTED TO SMELL FUMES, WE ALSO RECEIVED AFT LAVATORY SMOKE & MASTER CAUTION. FLIGHT CREW WENT ON OXYGEN & FOLLOWED SMOKE AT FIRE PROCEDURES. WE ALSO SHUTOFF THE LT PACK & THE FUMES & MASTER CAUTION CEASED. WE DECLARED AN EMER & CONTINUED. DEFERRED LT PACK IAW MEL 21-51-1B. PLACARD INSTALLED ENTERED INTO MMO2. R & R LT PACK IAW AMM 21-51-08. OPERATIONS & LEAK CHECKED GOOD. NO CABIN ODOR NOTED AT THIS TIME.