I have a few boxes that have built in wifi and I dont need it turned on. So I turn it off using the following command

nmcli radio wifi off

To make sure the wifi radio stays turned off in Cenots 7 after rebooting :

echo "/usr/bin/nmcli radio wifi off" >> /etc/rc.d/rc.local
systemctl enable rc-local.service && chmod +x /etc/rc.d/rc.local