Question

why did helen and other ghosts like her organise "the writer's inspiration bureau"

Answer 1

Helen was a writer in her other life. She suffered because of lack of ideas and inspiration. So, She with her co ghosts who suffered the same established an organisation called The Writer's Inspiration Bureau' to help those writers who were without ideas. After finding such writer's, the matter was brought to the attention of the main office and a ghost was assigned to it.