Question

why did the ghost want people to stop using the ouija board?

Answer 1

there is no any ghost.this is superstition.

Answer 2

The ghost initially had some extra time from their work so they had fun questioning answers from the people throught the Ouija board,but now many people started to use the board and ask many questions to the ghosts . So they are not able to relax now and do their work properly(like for Helen,helping others write stories).So now the ghosts want people to stop using Ouija boards.