When a grandparent dies, they came to the spirit are sons. Thus, the home of the Lanna and therefore make the "ledge sleeping" every home with a popular establishment is set high on the head of the House.
When the grandparents die spirit will linger over treat their children. The home of Lanna. It established a "shelf ghost grandparents" in every home by setting it high. Most popular establishment on the bed of the house.
when grandparents died spirit will continue to treat children. So, home of the Lanna. Thus prepared "ghosts" on every shelf grandparents house by set higher popularity set on to go home.