Bring a large pot of water to a boil. Cook pasta according to the package directions.
Meanwhile, heat a large skillet over medium heat. Dice bacon into small pieces and add to the hot skillet. Cook until crisp. Drain on paper towel.
In a large bowl, whisk together the ranch dressing mix, mayonnaise and milk. Set aside.
Once pasta is done, rinse well with cold water. Shake as much water off the pasta as possible. Add to the ranch mixture. Add bacon and cheese cubes. Stir well. Let sit in the fridge for at least an hour or up to overnight. Stir again before serving.