Preheat the oven to 375°F. Spray a 9x13 baking dish with nonstick spray.
Cook the pasta according to package instructions; drain.
In a large skillet, combine the milk, flour and salt. Whisk thoroughly to combine. Bring the mixture to a boil, whisking constantly. Cook for 1 more minute, until slightly thickened, stirring constantly. Remove from heat and stir in 3/4 cup of the cheese, stirring until melted. Set aside.
In another skillet, melt the butter. Add the garlic and cook over medium-high heat for 1 minute. Add the shrimp, wine and cayenne, and cook just until the shrimp begins to turn pink.
Add the pasta and shrimp to the cheese mixture and toss to combine. Spoon everything into the prepared dish. Sprinkle with the remaining cheese.
Bake for 20 minutes, or until the cheese melts and begins to brown. Let sit for 10 minutes before serving.
Weight Watchers Freestyle SmartPoints per serving: 10