Apart from a very small number of exceptions, it is IMPOSSIBLE for a departed soul to communicate with those on Earth through a medium or even to see or have any knowledge whatsoever of what is going on here. Even without going into complex metaphysical explanations, the truth of this assertion can easily be seen if we consider the following . . .
The place (or rather the state) of Heaven – called by the Tibetan name of Devachan in Theosophy – is one of supreme and perfect bliss and paradise. As such, logic tells us that no sorrow or even the slightest shade of pain can be experienced therein.
But if departed souls are able to “look down” or “return in spirit” and see all that’s going on on Earth and especially in their homes, what kind of bliss or paradise can that be? Thus, according to the doctrine of the Spiritualists, we unfortunate human beings are not liberated from the sorrows of this life even by death!
Imagine a departed mother looking down upon, or invisibly visiting, or automatically being attuned with, her former home, in the days, weeks, months, and years after her passing and observing and feeling – completely helplessly – the sorrows, the sadness, the suffering, the mistakes etc. of her dear loved ones, from whom she is now severed by death and unable to help, comfort, or contact. Or what about her eventually witnessing her widowed husband finding new love in the arms of another woman? Can any of this be bliss?!? That would be even more hellish than life on earth.
Thankfully, Nature is kind enough to create an impassable chasm between the Heaven state and the Earth state, so that those who have passed on are entirely out of the reach of physical existence and of individuals on the physical plane. A further and more expanded explanation of this is given in the articles When We Die and Death and The Afterlife which can be read by clicking on the title links.
* The above article is an excerpt from The Danger and Deception of Channelling. The “very small number of exceptions” referred to above are explained in the “When We Die” compilation.