Preheat oven to 350°. Prepare stuffing mixes according to package directions. Meanwhile, whisk together soup and milk.
Toss chicken with pepper; divide between 2 greased 13x9-in. baking dishes. Layer with ham, Swiss cheese, 1 cup cheddar cheese, soup mixture and stuffing. Sprinkle with remaining cheddar cheese.
Bake, covered, 30 minutes. Uncover; bake until cheese is melted, 10-15 minutes.