Getting a restraining order is a very big deal. It will cause your neighbor considerable hardship. If you merely feel uncomfortable, I would not proceed. Try telling him to leave you alone....
Civil restraining orders are much harder to get, unless you feel threatened by him for some specific reason. I think if you can have witnesses showing that he peeked into your window then you have a shot. Call an attorney and discuss the details. Initial consultation is free for most of us on AVVO so it will help you get an idea.
You can't get a restraining order because you don't like someone. If he's stalking you then that's another matter. I advise you to meet with an attorney to determine whether you can do something or not. Many reputable attorneys offer a free consultation.
The response above is not intended as legal advice since it’s impracticable to provide thorough, accurate advice based upon the query without additional details. It is highly recommended that one should seek advice from a criminal defense attorney licensed in your jurisdiction by setting up a confidential meeting. Moreover, this response does not constitute the creation of an attorney-client relationship since this message is not a confidential communication because it was posted on a public website, thereby publicly disclosing the information, which is another reason to setup a confidential meeting with an attorney.