Turn on/off WiFi via Mute switch I have jailbroken my iPad for firewall, XBMC and some development things only.

I didn't know before that on the right-hand side near the volume buttons is a switch. In settings I have two options for it: lock screen rotation or mute. I don't need either of them, but I've got an idea on my mind - how about to turn on/off WiFi with this switch? (To save some battery.)

Is there a mod or something that lets me do so?
Activator

You could try a custom action using Activator, set up to toggle WiFi when the Silent switch is double-toggled. 

I am currently not jailbroken myself (running iOS 7) and haven't used Activator for a while, but I remember that there is an option to activate an action by double-toggling the mute switch, as can be seen in the screenshot below.

There may be a way to activate it using a single toggle, but I am not able to find this out myself right now. Despite this, a double-toggle returns the toggle to its original point, meaning that you could use the toggle for WiFi and orientation/mute at the same time (a single toggle doesn't activate the double-toggle action).