Luis from Puerto Rico writes: How do I block an intruder in my WiFi?
Great question Luis! It’s very important to secure your home WiFi network and it’s equally important to make sure you are secure when you use a public WiFi network. This is the perfect opportunity to toot our horn here at WorldStart. Did you know we have thousands and thousands of articles on our website full of useful information? If you have a question, consider going to worldstart.com and searching the topic.
That’s what I did and I found some great articles to help you out.
Here’s one from the archive on Securing Your Wireless Network . It details the steps you can take to keep that home network safe and secure.
Here are some suggestion for staying secure on a public network. 
And this article has some great points about why it’s so important to have a firewall and how you can detect attempted intrusions. 
And there’s this helpful tip about how renaming your router  can provide more security. Hope these article help, Luis. If you have any more questions, let us know.