Living beyond the grave
Only someone who has fought for the light side can become a Force Ghost. Being able to influence solid objects and speak with the living beyond the grave sounds like cheat codes to us. It’s a pretty ridiculous idea, but it’s an important part of Star Wars.
What’s even stranger is that Darth Vader, the unequivocal evil guy of the original trilogy, also got his own Force Ghost. He couldn’t stand seeing Palpatine zap his son, Luke, halfway to death. So, in his dying moments, he tossed Palpatine into the Death Star’s reactor. His final 35 seconds of doing one good deed earned him his very own Force Ghost. Must’ve been awkward, meeting so many other people that he turned into ghosts.