Sautee onion on medium to low heat in butter or olive oil until soft.  Add garlic and sautee just a little.  Don't let it brown!  You can add some water and let it cook down if you need to.  Add in Cream of mushroom and celery and some milk to thin it out a little.  Melt in Velveeta cheese and add in salt and pepper as desired.  Add shrimp and cook slowly just until they turn pink and curl.  Don't overcook or they will be tough. You may need to add more cheese to thicken sauce.  Just use your judgement.  The shrimp will let out some water which will thin the sauce a little.   While preparing sauce, boil noodles in lightly salted water.  Drain noodles and add sauce to them.  Serve and enjoy!  This is delicious!!!