Preheat the oven to 325 degrees F. Coat a 2-quart baking dish with fat-free cooking spray.
Cook the noodles according to package instructions, leaving out any salt or butter. Drain and set aside.
Meanwhile, melt the margarine in a large saucepan over medium heat. Add the celery, mushrooms, red bell pepper, and green onions. Cook until tender (approximately 4 minutes). Add the turkey and cook, breaking up the meat with a spoon, until the turkey is no longer pink, about 5 minutes. Drain off any excess liquid.
Stir in the soup, teriyaki sauce, poultry seasoning, salt, black pepper, and red pepper flakes. Bring to a boil over high heat. Reduce the heat to low, cover, and simmer for 15 minutes, stirring often.
Stir in the sour cream and noodles. Pour the mixture into the prepared baking dish and sprinkle with paprika.
Cover with foil, and bake until heated through, about 15 minutes.