Updated June 10th, 2019.
I’ll bet you’ve accidentally connected to the wrong WiFi network a few times. Maybe it’s your neighbor’s unsecured network, maybe it’s something else. Avoid this problem by manually giving the networks you want to join top priority.
- First, go to Apple Menu/System Preferences/Network.
- Then, click on WiFi in the left-hand pane
- Then the Advanced… button
- The the WiFi tab
Now you see the list of networks your Mac has joined. They’re listed in priority order! Maybe the order is not what you want. If not, just drag networks up and down in the list to set their priorities. If you see a network that you never use just click on it and delete it using the minus button in the dialog box.
Your Mac will look for networks when it turns on or wakes from sleep, starting at the top of the list and working its way down. Obviously, your favorite network should be dragged to the top of the list.