Here is how you can do it, manually.
Find /etc/init.d/initswitch
Turn on wifi when switch on left side
Line 57:
"noop")
;;
*)
uci set wirless.@wifi-iface[0].disabled=0
uci commit wireless
wifi on
;;
Turn off wifi when switch on left side
Line 70 (before editing):
"noop")
;;
*)
uci set wirless.@wifi-iface[0].disabled=1
uci commit wireless
wifi off
;;