You shouldn't have you to kill it off as such.
What Avast version are you using Free or Paid version and build number ?
What are your windows network settings Private or Public, etc. ?
What would also help (determine what is the cause) is a screenshot of what it is that disturbs you ?
Have you checked the WiFi Inspector settings (as I don't get any intervention with my settings, attached screenshot) ?
Try that if it still continues uncheck the other option, but that one rarely triggers any popup.