As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSPECTION TYPE:ASN, CABIN DOOR OPEN LIGHT ILLUMINATED IN FLIGHT. ACARS SENSORS (MAIN CREW) CONFIRMED DOOR. AIRCRAFT MAINTAINED DIFFERENTIAL PRESSURIZATION. DOOR APPEARS CLOSED AND SECURE. REPLACED LEFT AFT SERVICE DOOR MICROSWITCH AND CHECKED PER 52-70.