What was found
IAH - FLIGHT 2508, THE CREW REPORTED A LANDING GEAR AIR/GROUND FAIL MESSAGE AFTER RETRACTION. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE RIGHT MAIN LANDING GEAR PROXIMITY SWITCH, OPERATIONALLY TESTED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.