She is coming for you
Song Yan was suddenly reminded of Madam Lin. Back then when she first started shooting her first movie, she saw Madam Lin being haunted by a ghost but the problem was that the ghost haunting Madam Lin was too strong and troublesome.
Because her cultivation was lower than the ghost, Song Yan avoided the ghost even when it came to attack her.
After that she completely forgot about Madam Lin and the ghost as she went ahead with her life, Madam Lin also never asked for help. As the heavens only allowed her to help those who wanted to help themselves, Song Yan couldn't forcibly exorcise ghosts.
Sometimes some humans have attachments to the ghosts that were haunting them. So even if a master was to exorcise them, those humans might jump the gun and cause harm to themselves.
Because of this many masters would turn a blind eye to such things unless the humans had no idea that they were being haunted.