As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) APPROXIMATELY HALF WAY TO DESTINATION, INBOARD ROLL SPOILER HYDRAULIC CAUTION LIGHT ILLUMINATED. OPERATION OF SPOILERS APPEARED NORMAL. AIRCRAFT RETURNED TO DEPARTURE AIRPORT. MAINTENANCE REPLACED ROLL SPOILER INBOARD HYDRAULIC PRESSURE SWITCH.