According to legend, there is a kind of ghost called "substitute ghost" who usually lurks in human society. Once it focuses on a target, it will hide in that person's body, follow him for a day, and become familiar with his daily schedule.
The next day, the substitute ghost takes his body and imitates him doing the same actions as usual. Once someone questions "whether you are him or not" during the day, the substitute ghost has to leave that person's body. If no one questions it within 24 hours, the substitute ghost can occupy this body indefinitely until it meets its next favorite target.
Everyone around you may no longer be the same person.
Conception:
Give me tea 23333
Things are changing haha