If during a ouija session an entity gives a date for when they were or still think they are alive, having a database of events and cultural markers (music of the time, slang, attitudes, food) could be used to elicit a two-way swap of likes and dislikes and beliefs, even the playing of theirs and your music. Educating the dead on how things have changed culturally might produce some interesting outcomes.
Entity: 'I was/am married'
Yvette: 'To a woman?'
Entity: 'Of course'
Yvette: 'I ask because nowadays, in our time, women can marry women'
Entity: slams door
More could be driven through interactions. Fun times :)