I think my new neighbors are stealing my WiFi?

[CJ]

Definitely secure your wifi with a password. If you're unsure how to do this, simply go to CMD and type "ipconfig" and hit enter. Find your IP address (Default Gateway) and type it into your browser. That should take you to your router's admin page. If you need a password, just Google it and find the default login/pw (if you haven't secured your network, chances are it still has the default admin/password). From there you should be able to not only set a password, but also see which devices are connecting (meaning you can check it next time the neighbor is standing outside near your home to see if he is indeed connecting).