Have you ever gone to a big public place like an airport or an arena? You know they have hundreds of APs. But when you try to connect you only see 1 AP (SSID) instead of the hundreds that you know are there.
This is where an evil genius would ask, “What will happen if I started a wifi hotspot with the same SSID?”
This is called an evil twin attack. When a device tries to connect to an SSID it will connect to which ever device has the strongest signal. This is normally the closest AP. This type of attack works best in a place that offers free wifi.
Once someone connects to your evil twin AP, you can sniff their traffic and get all of their credentials. If the user checks their banking information, then now you have all of their banking information.
Always be very careful when you use “free public wifi” you never know who could be watching you.