What is the best way to describe services in terms of MVVM?

Question

WPF

I used to produce all the logic inside the service, but when I switched to MVVM, I started doing this: I make the service events corresponding to the called contract functions and call them, and already somewhere outside in the model I create an instance of the service, bind to these events and process them. So I'm wondering how this approach is correct? It is in the context of MVVM how to do it correctly?