As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) FILTER LIGHT CAME ON UPON LANDING. REMOVED FILTER AND INSPECTED. NO CONTAMINATION FOUND AND TEST LIGHT CIRCUIT. A LIGHT CAME ON AGAIN AND UPON INVESTIGATION, IT WAS FOUND THAT THE SWITCH WAS CORRODED. A NEW FILTER ASSY. WAS INSTALLED AND TESTED. IT FUNCTIONS CORRECTLY. INCIDENT HAPPENED 35 HOURS AFTER 300 HR INSP, WHICH INCLUDED FILTER CHANGE.