Preheat the oven to 350 and lightly grease a 9x13 baking pan or casserole dish.
Cook pasta to al dente according to package directions, drain and set aside.
While the pasta is cooking place your milk, cream cheese and ranch dressing mix in a medium size pot. Heat on low-medium heat stirring frequently until the cream cheese is melted completely and all of the ingredients are incorporated.
Spread the cooked pasta in the bottom of your prepared baking pan.
Spread the cooked chicken evenly over top of the pasta.
Then sprinkle the cooked bacon evenly across the top of the chicken.
Pour the creamy sauce evenly over everything, gently stir to work the sauce into the chicken and pasta.
Evenly sprinkle the cheddar and mozzarella cheese across the top of the casserole.
Place in the oven and bake for 15-20 minutes or until the cheese is warm and bubbly and the casserole is heated through.