An old Breton tradition that may have once extended to other Celtic areas, such as Cornwall and Wales.
Bretons believed that the dead watched over their descendants, and because of this, people would seek guidance from their ancestors before making any major decisions through the use of a Listener.
Listener to the Dead was a well-respected profession which involved acting as a medium between the living and departed, passing on the messages of the deceased to their still living family members. It wasn't uncommon for each village to have one.
The practice continued until the early 20th century.*
*Although one could argue that it still continues today.