What was found
(CAN) ACFT EXPERIENCED A WING OVERHEAT LIGHT IN CRUISE. DURING THE INVESTIGATION INTO THE CAUSE OF THE OVERHEAT LIGHT INDICATION, MAINTENANCE DISCOVERED THE CONDITIONED AIR MIXING VALVE FOR THE AFFECTED SIDE TO HAVE ITS BUTTERFLY VALVE STRIPPED ABOUT ITS SPLINED DRIVE SHAFT. THIS WOULD ALLOW THE VALVE TO TRAVEL TO A FULL 90 DEGREES WHERE ITS NORMAL FULL OPEN TRAVEL IS 30 DEGREES. THIS CONDITION WOULD ALLOW FULL HOT AIR INTO THE CONDITIONED AIR DUCT INTO THE CABIN AND CAUSE THE WING OVERHEAT SENSOR TO ILLUMINATE THE WING OVERHEAT WARNING LIGHT.