"Ground" is an arbitrarily-chosen voltage convention. In space the floating ground won't cause a fault because there's never an electrical circuit with both the floating ground and the 'real' ground.
EDIT: turns out the ISS is a bit more complicated than that, and it also has a "grounding strap" that connects to the local plasma. https://news.ycombinator.com/item?id=41417136
Fun tidbit, old English cars (and the original Ford Model A!) used to tie positive DC to the frame rail as a “ground” or “common” instead of the negative DC. They are referred to as positive ground cars (and tractors!)
https://www.restore-an-old-car.com/positive-ground-cars.html
Busses also (used to?) have ground straps that you may see dragging. Apparently this was somewhat common on cars as well. "bus ground strap" is unsurprisingly difficult to search for, but I did find a discussion on Quora [1] that claims rubber formulations were responsible for vehicles picking up a static charge.
All of this is interesting once seen as an attempt to remove the potential difference between local "ground" and ambient environment.
[0] https://en.wikipedia.org/wiki/Static_wick
[1] https://www.quora.com/Cars-used-to-have-grounding-straps-han...