since most people are still using IPv4 most households and ISP's share from a limited pools of addresses(These change every few weeks, unless you requested a static domain which costs$$), the router breaks it up into blocks of /16^2 (254 theoretical devices can share the same IP) usually starting with 192.168.x.x, or 10.x.x.x, you can find your Local IP address by going into Command Prompt(for windows) or Terminal(*nix systems) and typing ipconfig or ifconfig respectively. this is your internal IP address, that most hackers, won't be able to see(unless you use wep, or lower encryption). To find your external IP address go to google and type "Whats My IP". Also if the hacker knows where you live, and has access to your FB/email wouldn't they already know who you are?