1. Spray slow cooker lightly with cooking spray.
2. In large bowl, combine cheeses and set aside.
3. In another large bowl, whisk eggs lightly. Add evaporated milk, milk, dry mustard, cayenne, nutmeg, salt, and pepper. Whisk to combine.
4. Add 3 cups of cheese mixture and uncooked macaroni noodles to egg mixture. Stir to combine.
5. Pour into slow cooker. Top with remaining cheese.
6. Sprinkle with paprika.
7. Cook on LOW for 4 hours.