As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CAPTAIN REPORTED A FIRE IN THE CABIN AT THE L1 DOOR AND TAXIED THE AIRCRAFT BACK TO THE GATE. THE FLIGHT ATTENDANT USED THE FIRE EXTINGUISHER ON A BURNING NAPKIN IN THE OVERHEAD LIGHT FIXTURE. THE NAPKIN REMAINS WERE REMOVED BY THE FLIGHT ATTENDANT. MAINTENANCE REPLACED THE BULB AS A PRECAUTION, INSTALLED A MISSING LENS, AND REPLACED THE EXTINGUISHER. THE AIRCRAFT HAS RETURNED TO SERVICE.