Does he spray at all in the cat room? Could you put a litter box where he sprays as a hint to use that instead of the walls? I had a male that would not squat to pee, so I needed to get all covered litter boxes so the stream would hit the lid and run into the box, instead of hitting the wall behind the box. All in all, I would try a vet visit to check for medical problems or medicines that calm him if it is behavioral. But try to gather as much info as to when and where he does it. who is nearbyu at the time ANYTHING!!! Best of luck