Have you ever had a dream that inspired you to write a story?
Your heroine is having creepy dreams. They’re so creepy that she’s compelled to write them down. The writing is partially therapeutic. However, when she writes it is almost as if she is in a trance, as if someone is writing through her.
Start your story with her writing. What is she experiencing? Who is haunting her and why?
For example, maybe she’s being haunted by a woman who wants to reunite with her lover who is still alive. The dreams lead your heroine to seek out this lover and maybe they start something romantic. Then your heroine has to deal with an angry ghost!
That’s just an idea. Have fun with it!