How do I prevent unauthorized access to my home wifi?
The best thing you can do to prevent unauthorized access to your home wifi is to make sure that the network id (or SSID) is password protected (using a complex password). Also make sure the wifi router is password protected.
There are advanced options, such as not broadcasting the network ID. What this is does is prevent systems from automatically detecting the wifi network. You have to manually join the wifi network (assuming you know the network ID).
Also check the list of devices that are connected to the wifi router. If you do not recognize a device, then either disconnect it or block it.
Not broadcasting the network ID (after changing the passwords preferably using the WPA2 encryption protocol that should be standard on your router/wifi) is one of the best steps to take to protect your home wifi.
Also super important are to change the default password for administrative access to your router/access point, and DO NOT USE the same password for WiFi and administrative access to the router.