As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH INTO SLC, AMBER GEAR DOOR LIGHT CAME ON AFTER GEAR WAS EXTENDED. CREW DID GO-AROUND DURING WHICH GEAR DOOR LIGHT EXTINGUISHED. EMERGENCY EQUIPMENT REQUESTED AS A PRECAUTION. FLIGHT LANDED WITHOUT INCIDENT. CLEANED DOOR SWITCH AND OPERATION CHECKED GOOD.