As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMBOUT THE FLIGHT ATTENDANT REPORTED A LOUD SQUEAL FROM THE MAIN CABIN DOOR AND THE PASSENGER DOOR WARNING MESSAGE ILLUMINATED INTERMITTENTLY. THE CREW FOLLOWED THE QRH, RETURNED TO FAY, AND LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED A GOB OF CHEWING GUM FROM THE DOOR SEAL AND PROXI-SENSOR AREA. THE PRESSURIZATION AND DOOR INDICATION SYSTEMS OPERATIONALLY CHECKED GOOD. THE AIRCRAFT WAS RELEASED FOR SERVICE.