As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: DURING CLIMB PASSING THROUGH 18500, DOOR 3R EMERGENCY EXIT LIGHT ILLUMINATED FOR A FEW SECONDS THEN NORMAL NO CABIN PRESSURE ISSUES. MAINTENANCE REPLACED THE R3 DOOR DETECTOR PROXIMITY SWITCH PER AMM 52-71-13