The Watchtower Society has a history of claiming the involvement of dead members in the furthering and understanding of truth.
From The Finished Mystery on page 144:
“Though Pastor Russell has passed beyond the veil, he is still managing every feature of the Harvest work. `THE WATCH TOWER BIBLE AND TRACT SOCIETY is the greatest corporation in the world, because from the time of its organization until now the Lord has used it as His channel though which to make known the Glad Tidings'"
The Watchtower from November 1, 1917, states this under page 6161 from the reprints by the Watchtower Society:
“Hence our dear Pastor, now in glory, is without doubt, manifesting a keen interest in the harvest work, and is permitted by the Lord to exercise some strong influence thereupon.”
Is this just an incorrect understanding which was refined and corrected with time? No.
Over 70 years later, similar claims are still made. Yes, even current “light” from the Watchtower Society includes how the dead is involved with the receiving of truth.
According to Revelation – Its Grand Climax At Hand! - Both the original 1988 and 2006 revision - on page 125 it states:
“It is fitting, then, that one of the 24 elders representing anointed ones already in heaven, should stir John's thinking...(Revelation 7:13, 14a) Yes, that elder could locate the answer and give it to John. This suggests that resurrected ones of the 24-elders group may be involved in the communicating of divine truths today.”
This means throughout the organization’s history, as well as remaining the current teaching, the Watchtower Society believes and teaches that dead anointed members (those of which according to Watchtower Society doctrine are of a literal 144,000 individuals) have involvement in communicating divine truths to living Jehovah’s Witnesses.
Not only does the Watchtower Society lack any moral authority to condemn any organization or person for practicing Spiritism, they are hypocrites and liars to claim they do not engage in such practices.