[member="Boulder"]
The Ghost is wholly peaceful, a former Je'daii/Jedi Master, however yes she could provide him with some insight if necessary. There would need to be a good reason for her to do so though, such as him already having been possessed / something having attempted to possess him. She doesn't like to interfere.
It would be done through [member="Raseri Sarosh"] though, as I don't have an account for the character (She's long since dead) and would rather her come to initially visit her son and then realise that Boulder needed help
If that makes sense?