Note - This recipe makes more than 4 servings.
In a large bowl, toss chicken with the ranch dressing mix and set aside.
Spray the inside of your slow cooker with cooking spray and turn to high.
Place the milk, cream cheese and cheddar cheese in the slow cooker; stir. Let sit for 30 minutes and mix again.
Add the uncooked pasta, buffalo sauce, chicken and salt & pepper to taste.
Stir all the ingredients together so that all the pasta is coated and covered by the milk. Turn slow cooker to LOW, cover and cook for 3-4 hours or until pasta is tender. Stir halfway through cooking.