Pilgrim

I have a 91 cherokee that has been monkeyed with by a (probably stoned) kid. The electrical system has been ripped apart and jerry rigged back together with all sorts of horn buttons, toggle switches etc. It was running this morning, I smelled something and then everything died except interior lights, horn and possibly (I didn't look) headlights.

Any suggestions as to where to begin to get it running again?