Yoda called lighting to strike the jedi temple as a force ghost in The Last Jedi, guess its probably something to that effect. Obiwan tells Vader in a New Hope that if he gets struck down, he'll become far more powerful than he could possibly imagine and we know Qui-Gon teaches Obi-wan how to become a force ghost at some point. I'm guessing force ghosts can do some crazy stuff, they've never really expanded upon it much until The Last Jedi when Yoda smacks a depressed Luke with his cane and then force calls lightning that strikes the Temple, setting it on fire.