Brown sausage in a small skillet, stirring to crumble; drain well, and set aside.
Melt 1/4 cup butter in a large saucepan over low heat; add flour, stirring until smooth. Cook 1 minute, stirring constantly. Gradually add milk; cook over medium heat, stirring constantly, until thickened and bubbly. Add paprika, salt, pepper, and turkey, stirring well.
Spoon half the turkey mixture into a well-greased 1 1/2-quart casserole. Sprinkle half the sausage over turkey. Repeat layers; sprinkle top with breadcrumbs, and dot with 1 teaspoon butter. Bake, uncovered, at 400° for 30 minutes. Serve with cranberry sauce, if desired.