Heat oven to 350°F.
Cook pasta according to package directions. Drain. Set aside.
Melt butter in 2-quart saucepan over medium heat; stir in flour 1 minute or until smooth and bubbly.
Stir in chicken broth; continue cooking, stirring constantly with whisk, 4-5 minutes or until mixture comes to a full boil. Boil 1 minute.
Remove from heat. Stir in 1 1/2 cups cheese until melted.
Stir in milk and hot pepper sauce.
Combine cheese sauce with cooked spaghetti, turkey, broccoli and mushrooms in greased 2-quart casserole. Top with remaining cheese.
Bake 25-30 minutes or until bubbly around edge.