This first video gives you a pretty good idea on how to get the wing bone parts you need out of the turkey and the following video will give you some ideas on how to assemble the call in terms of what the finished product looks like.
This video shows a finished wing bone call and the author gives a good demo of what you can do with a call like this. It is belived the Native Americans were the originators of the wing bone turkey call.
Turkey Call Made From A Rubber Glove & Pill Bottle
Homemade Turkey Wing Bone Call
Making A Turkey Box Call At Home