Cases of Jedi Force Ghosts fighting Sith?

Anything like that?

Or even the other way around?

https://www.youtube.com/watch?v=dH_ip7-NL9k

...In the main timeline, that actually happened.

Sidious escaping from Chaos and the Jedi that apparently attempted to hold him there? *Shrug*

Spirit Luke helped defeat spirit Exar.

Spirit Vodo helped defeat Exar as well.

I thought he just showed up at the end.