Your computer has no idea which wireless networks are yours. It just tells you which networks it sees, which will be any network close enough for the signal to reach. If you're in an apartment building, that can be a LOT of networks.
I could see two dozen networks in my old college apartment. One day a new one popped up without any security turned on named "Hi, I'm a network!". I logged into their router and changed the name to "Hi, I'm an insecure network." The next day they'd secured it and changed the name to "I'm just a network, you're mean."