Im affraid things aint that simple regarding spirits. Not all spirits have direct access to this our world, and the little I have experienced dmt shows me that dmt has a realm of its own, which is far from ours.

If you are intetested in this subject of spirit contacting and empirical evidence, I suggest you to research "spirit evocation".

[URL unfurl="true"]http://imperialarts.livejournal.com[/URL]

That website will give you an idea of what it is about having real contact with spirits in our own realm.