Couple Voltage Issues in Circuit...

Ok so we just bought a really old building, and part of it was recently finished as a one bedroom apartment.

Nearly every single wall is on its own circuit. Literally. And the place is max 500sq ft.

The bathroom and kitchen share a wall.

Two outlets one on bathroom side, one on kitchen side both pull 150 volts at the outlets (GFCI) then two more in the kitchen on a seperate wall (supposedly seperate circuit) only pull 89 volts.

Both walls being exactly 30 volts under and 30 volts over....

Also when one breaker is turned off the other circuit still pulls between 5-11 Volts, when both circuits are off they pull zero?

I discovered all of this trying to figure out why the GFI's werent working, but now ive got a whole new problem?

Also, the two outlets pulling 150 are closest to the breaker box, and before the other two 89 volt outlets if they do share some kind of line.

Im kind of at a loss as to why this would happen, and what to do to fix it?