As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE NR 1 ENGINE FIRE LIGHT ILLUMNIATED IN FLIGHT. GROUND CHECKS WERE BEING PERFORMED FOR FIRE LIGHT ON PREVIOUS DAY. ACFT WAS IN HOVER WHEN LIGHT ILLUMINATED AFTER REPLACING FIRE LOOP ON PREVIOUS DAY. MX PERFORMED ADDITIONAL TROUBLESHOOTING AND DISCOVERED THE INSULATORS CONNECTING THE FIRE LOOPS WERE WORN ALLOWING A SHORT.