My 14 year old male cat sneezes and scratches all the time. He is an indoor cat and never goes out. He eats and poops well but the constant sneezing and scratching is getting out of hand. On a fixed income and don't really want to pay a fortune to a vet.
It sounds like your cat has allergies and is having an allergic reaction to something in the household. I did a page on this and the link follows: