Is there an easy way to track where switches go/do?
I assume there must be a main breaker panel somewhere. Start by tripping all breakers, shutting off electricity to the whole house. 


Activate a single breaker. Walk all over the house, seeing what still seems to work. Note that on a (large) drawing. Make extensive notes.
Deactivate this breaker. Activate another. Repeat until finished.


This should give you a rough view of what goes where. If there are smaller breaker panels hanging off the main panel, go through the same process.

Some types of detector can help detect live wires, even beneath wall panels. This was on Amazon 

(disclaimer: I have never used this particular type.)

By the way, I also assume there must be a building code where you live? And a part of that relating to electrical installations? And that insurance will not cover you for damage (i.e. fires) caused by installations that do not conform to code? You get where I'm going with this. 

HTH