Iphone XR Rings when my wife receives a call

Stop sharing an Apple ID with your wife. You shouldn’t for many reasons, this being only one. Instead one of you get a different Apple ID, then share what you want to share with Family Sharing, and don’t share what you don’t want to share, such as personal text messages, photos, contacts, etc.

It sounds like you both may be using the same Apple ID and have Settings > Phone > Calls on Other Devices Allow Calls on Other Devices turned on.

If so, turning that off will solve that one problem -- but you are likely to encounter other issues by sharing an Apple ID.