Great-grandfather and the Spirit of the Table

My great-grandfather summoned a dead person to find out if his brother Mate was alive. Mate was married but he was hiding from the Partisans and the Ustaše because he didn't want to go to war. He was hiding in caves (škripovi) and in attics. But his wife had a brother who was a Partisan. He came once and asked her where Mate was, acting like he wouldn't tell anyone. She told him, and the Partisans took him away.

Then my great-grandfather took out a wooden table and summoned a dead woman he knew from before while she was alive. He asked her: "Is my brother alive?" She said that the Partisans were cut off by the Ustaše and they took Mate. Later, he found out that Mate died somewhere near Travnik under an Ustaše cap and badge.