What was found
CREW REPORTED DURING CRUISE FLIGHT, GEAR UNLOCK LIGHT ILLUMINATED. GEAR WAS CYCLED ONCE WITH SAME INDICATION. GEAR WAS SELCTED DOWN, THREE GREEN DOWN AND LOCK LIGHTS ILLUMINATED BUT GEAR UNLOCK LIGHT REMAINED ILLUMINATED. AIRCRFT RETURNED TO KBOS WHERE MAINTENANCE INSPECTED AIRCRAFT AND RELEASED AIRCRAFT FOR SPECIAL FERRY FLIGHT SO THAT RETRACTION AND EXTENSION CHECKS COULD BE PERFORMED. MAINTENANCE FOUND NOES GEAR UPLOCK SWITCH HAD FAILED. SWITCH TO BE REPLACED AFTER OTHER MAINTENANCE IS PERFORMED.