Mediumship

The mother is a spiritualist—has been for years—and, being on the lookout for it, naturally discovered what she calls 'mediumship' in Viola when a child.

Source: wiktionary

"I may add that in my own domestic circle, under my wife's mediumship, we have been privileged to bring hope and knowledge to some of these unhappy beings."

Source: wiktionary

But for myself I do not regard mediumship very favourably.

Source: wiktionary