Cook macaroni according to package directions, drain. Meanwhile, in a medium, saucepan melt butter over med-low heat. Add celery and onion, cook until tender. Blend in soup, milk and cheese. Cook until the cheese is melted. Combine cheese with macaroni, turkey, and salt. Spray 3 q casserole dish with non-stick spray. Transfer to baking dish and top with crushed potato chips. Bake 350 for 30 min or until hot and bubbly and the chips are toasted.