I have a file with an .svc extension. First question is what is a .svc file? The second question is how do I create one of these from the Visual Studio add item menu? I've tried all the most obvious options but none of them create a .svc file.
In my experience, an SVC file is a WCF service - create a WCF application from the projects list and then do an "Add new item" and add a new WCF service.
For it to do anything it will need the appropriate bindings and endpoints configuring and wiring up - before it can be called.
See also: WCF service. Where to add . svc file