Spiritualism is conjuring up the dead. He didn’t do that. Necromancy is using the spirits of the dead to tell fortunes. He didn’t do that, either. At least get your definitions straight.
There’s no need to be a stickler for definitions, because the Bible forbids ALL occult activity involving any type of communion with the dead. Doesn’t matter whether you conjured them up, or they showed up of their own accord, you aren’t supposed to sit down and have tea with them, if you are a Christian.
Your definitions are wrong. It’s not simply fortune telling etc, talking to the dead in any way shape or form is anti biblical. We are told not to do this.