Where in the Law does it say 'except they be in a certain place'? Right, it doesn't. Furthermore, you don't know where they are - OOPS. Just kills your protest there flatly. The Law says no speaking to dead people [(period) end of statement]. No exceptions. No 'if you eat your dinner we'll see' parachutes for you. Praying to dead people is a flat bold violation of God's law.
Now, the Jews know this. The Christians know this. And the Protestants know this. Why is it that Catholics don't. Or is it that Catholics don't care or think that their clergy has some spiritual right that even Jesus didn't have to Contravene scripture. Even Jesus recognized that the law was from God. Do Catholics not recognize the Law?
Once you understand that, I guess you object to talking to the dead, eh? Jesus talked to Moses and Elijah at His Transfiguration. Now Elijah was taken alive into heaven, so I guess he was (and is) still alive (even according to you--I know on the basis of Holy Tradition that he is). But Moses died. Thus Christ Himself provides and example of speaking to the dead, and are we not to imitate Christ in all things?