How do I turn off all Wifi on my router

I know how to turn off the 2.4 and 5Ghz visible channels on my router, but when I do this there seems to be 'hidden' Wifi channels ... or whatever they are called ... because the strength of my router signal goes way up.  All of the various meters I've used show it goes up into the very dangerous zones.  My goal is to have no Wifi and only use Ethernet cable.   How do I disable all Wifi signals on my router... seen and unseen???