In a large slow cooker, mix together the cream of celery soup, French onion soup, and sour cream. Stir in the meatballs. Cook on high heat for 3-4 hours.
Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain. In a large bowl, toss the pasta with butter. Serve meatballs and sauce over the cooked pasta.