OT home wiring

I know that are a lots of electrical types out there so a quick OT question.

Stopped by a friend's cottage and she asked me if I would add a circuit in her garage so she can have a freezer etc..

It's a really old cottage. The mains are not the basic lay out. The neutral and ground buses are on top of each other and what I found strange is that all of the ground and neutral returns for a given circuit go to the same bus. That is the neutral and ground is wrapped and returned to one bus or the other. No rhyme or reason as far as I can tell. She thinks I'm an electrical genius because she listens to an old pair of two-way speakers I made years ago(hehe). I don't want to break the spell. What's up? What do I do now?

(yaya, I know-call an electrician)

TIA
I remain,