God makes it very clear....”The person who turns to the spirits of the dead and familiar spirits to commit prostitution by going after them, I will set my face against that person and cut him off from the midst of his people....Lev. 20:6
It would then cause one to wonder who intercepts these prayers to saints....since only Jesus is our intercessor...and how do they know they're being heard? I believe it is possible their prayers are intercepted by "the dark side" who love to imitate the departed...and anything or one that would keep people from speaking directly to God.
One would think that would be a sombre message to Catholics.