Where does the soul go during sleep?

Do Spirits sleep as mortals do—that is, lose consciousness?

Well, we certainly give our senses a rest—you may call it sleep if you choose, but we are as much awake as I am now, only not active. Your Spirit, when your body is at rest in sleep, is quite active. You awake during the night with what you consider a vivid impression of a dream, but you sleep again, and all disappears on again waking up—that was no dream, it was something carried back from Spirit life. Then you have what is called nightmare—that is caused by a stoppage of the circulation in some part of the body. There is yet another state from which you are aroused with a feeling of inextricable and absurd confusion of places, persons and things. That arises from disorder in the stomach, which by the nervous system is closely connected with the brain, so that when there is disorder in the stomach, you have what is called dreams. But those vivid impressions, which I have said pass away, are visions of the Spirit.

—Ruisdal—or Steen in Spirit