Drain chicken and crush chunks with a fork. Heat chicken and hot sauce over medium heat until heated through. Soften cream cheese and cut in chunks. Stir the cream cheese and ranch dressing into the chicken mixture and cook until well blended and warm and the cream cheese is melted, stirring occasionally. Mix in half of the shredded cheese and stir until melted. Transfer the mixture to a slow cooker or a baking dish. Sprinkle remaining cheese over the top, cover, and cook on low setting (in slow cooker) until hot and bubbly OR in oven on 350 for 30 minutes until cheese is completely melted on top.
Serve immediately with celery sticks, crackers, or tortilla chips.