What was found
CLT - FTL 2703 - EN ROUTE FROM BWI TO MIA, A LOUD SQUEALING NOISE BEGAN COMING FROM THE AFT LEFT ENTRY DOOR. NOISE WAS LOUD ENOUGH TO SCARE PASSENGERS AND IT WAS ALSO HARD TO COMMUNICATE. FLIGHT DIVERTED TO CLT AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE REMOVED DEBRIS AND LUBRICATED THE AFT LEFT ENTRY DOOR SEAL WITH SOAPSTONE. PRESSURIZED AIRCRAFT. LEAK CHECK SATISFACTORY. (M)