As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NOSE GEAR INDICATED BOTH RED AND GREEN LIGHTS ON WHILE LANDING GEAR LEVER WAS MOVED TO UP POSITION. AIRCRAFT GROUNDED. TROUBLESHOT THE NOSE GEAR INDICATION IAW AMM 32-61-00 P101. FOUND A FAULTY NOSE GEAR PROXIMITY SNESOR. REMOVED AND REPLACED THE SENSOR IAW AMM 32-61-51. PERFORMED A GEAR SWING. OPS CHECKED GOOD IAW AMM 32-61-00.