What are the Old Testament passages about not contacting the dead referring to?

There are some passages in the Old Testament that condemn resorting to mediums and some other practices (Deuteronomy 18:10-12, Leviticus 20:6, 2 Kings 21:6, Isaiah 8:19, etc.). The passages are sometimes brought up in discussions of prayer to saints.

It's popular to take the passages as addressing something narrow like seeking information about the future or trying to get the dead to verbally communicate with you, something that isn't being done by those who practice prayer to saints. And advocates of praying to saints often argue that the saints being prayed to are spiritually alive. It supposedly follows that even if the passages under consideration are about trying to contact the dead in a broader way that goes beyond something like seeking information about the future or trying to get verbal communication from the dead, the passages aren't relevant, since the saints in heaven aren't dead in the way that matters. What should we make of those responses?

Ancient Jewish Sources On Praying To Saints And Angels

For many years now, advocates of prayer to saints and angels have been citing an article by Meir Bar-Ilan that discusses ancient Jewish belief in prayer to sources other than God. You can read that article here. But Bar-Ilan also mentions other ancient Jewish sources who advocated praying only to God. And he says that their belief was earlier and Biblical. For example:

How Afterlife Issues Affect Claims About Prayer To Saints

People often overlook some of the evidence that's relevant to evaluating prayer to saints. After praying to saints became popular (with ongoing opposition), other issues continued to prevent some people from accepting it and led others to accept significantly different forms of it. In a book about the cult of the saints, Matthew Dal Santo discusses how differing views of the afterlife led to what he calls "radical" and "profound" differences in how people viewed prayer to saints (Debating The Saints' Cult In The Age Of Gregory The Great [United Kingdom: Oxford University Press, 2012], 308, 315). A belief in soul sleep could prevent one person from believing in prayer to saints and lead another person to believe in it, but in a significantly different form than what's advocated by, say, modern Roman Catholics or modern Eastern Orthodox. Or think of purgatory. There are connections between purgatory and Catholic views of prayer to saints, what saints are doing in heaven, and such. Think of prayers to saints that ask them to help those in purgatory or purgatorial apparitions that supposedly referred to the saints' intercession for those in purgatory, for example. But many pre-Reformation sources rejected purgatory. Go here for a post that quotes some of Dal Santo's comments on the diversity of afterlife views held by pre-Reformation sources, including for hundreds of years after prayer to saints became popular.