Is there a ghost on Huaqiang Honglian?

Huaqiang Honglian is a Korean thriller, which I couldn't understand when I watched it in the cinema before. I thought it was a ghost film, but it wasn't. In fact, there are only two people, sister and father, and the rest are illusions. There is no ghost in the whole film. The ghost my sister saw was her illusion, and the stepmother saw it because there was a ghost in her heart. Lin Xiujing's sister died a long time ago, but she always thought her sister was still alive. Since her mother was killed in the closet, she began to have hallucinations and auditory hallucinations. She has been living in an illusion of her own imagination. Before the end of the movie, all the scenes of her stepmother were Xiujing herself. The story is also interspersed with romance, and the last movie tells us the truth of the story. In a word, the wonderful and ingenious thing about this movie is that you don't believe your eyes most of the time when you watch it.