Not long ago someone called and needed assistance with their Apple computer and Wifi. I arrived on-site and the client explained how they were hacked. Someone near their location got into their Wifi network and possibly their Apple computers. We talked about improving their security and I discussed turning off their Wifi network and using wired ethernet for their Apple desktop computer. They liked this idea so I disabled the Wifi and connected an ethernet cable from the wireless router to the Apple computer. They can do everything they could before and their network is going to be harder to hack now.
If it ever needs to be on again in the future, WiFi can be enabled from the Router admin console just like i did to disable it. If you don’t need wifi than disable it and you’ll be safer.