A movie about European castles

She couldn't remember the plot clearly, only a rough idea. The mother brought her children to live in the castle, but they found that there were ghosts harassing them in the castle. They were harassed every day. At the end of the movie, the truth was revealed. It turned out that the mother, son, and daughter were the ghosts. They used to live in the castle and were killed for some reason. After they died, they were unwilling to leave the castle. The ghosts in their eyes were actually normal people who were scaring each other.