In this case, you should modify /usr/bin/wifioff file.

#!/bin/sh
device=$(uci -q get wireless.@wifi-device[0].disabled)
ap=$(uci -q get wireless.@wifi-iface[0].disabled)
if [ "$device" = "1" -o "$ap" = "1" ]; then
        uci set wireless.@wifi-device[0].disabled=0
        uci set wireless.@wifi-iface[0].disabled=0
        uci set network.wan.disabled=0
else
        uci set wireless.@wifi-device[0].disabled=1
        uci set wireless.@wifi-iface[0].disabled=1
        uci set network.wan.disabled=1
fi

uci commit wireless
uci commit network

wifi
/etc/init.d/network reload