Here's a very handy, functional NoCC Divination Table! It is shared as a room of course, so look for it on the rooms filter.
You can add more chairs (it's a table for six) if you want to (you can also remove these chairs and put other ones).

First, click on the ball (it's the scientist-created lamp) and once it floats up you can click on the ring, which brings the ghosts. Don't tell your sims this is scamming them, let them think those are real ghosts.