Well, when you look at the events surrounding the 'Poltergeist' movies, there were a number of rather strange and tragic occurrences. There were deaths and accidents among the cast. The media loves a good story, and they latched onto these events. They started to connect the dots and create this narrative of a curse. As the stories spread and more people talked about it, it became a significant part of the True Hollywood Story. It's a combination of real - life tragedies, media attention, and the public's fascination with the idea of a Hollywood curse.
The curse of the Luo family was to protect Luo Zhaoyan by sacrificing the lives of the other members of the family in order to break the curse of the twins. Luo Mingmei used the entire Luo Clan (excluding Luo Zhaoyan) and his own death to remove the curse, allowing Luo Zhaoyan to live a normal life. The specific method to break the curse was not mentioned.