All praise be to Allah.
There is a myth that many people believe that the soul of the deceased return his home and to his family for the 40 days.
We as a Muslims must understand that when a person dies he moves from this world to the realm of another world. His soul does not come back to his family and they do not feel anything of him.
This fact that a soul returns his home is a myth that has no basis in Islam. Similarly, the dead person does not know anything about the circumstances of his family, because he is absent from them, in a state of bliss or torment.
But Allah may inform some of the dead in some of the circumstances of their families but not necessarily always and every time.
There are some reports on such incidents but these cannot be relied upon. According to these reports, the deceased may know something about his family’s circumstances. However, the reports are not reliable.
With regard to dreams about dead relatives, some of them are true and some are the playing of the Shaytaan. The living may come to know something of the circumstances of the dead via true dreams, but that depends on the sincerity of the one who sees the dream, whether the dream is a true dream and the ability of the one who interprets these dreams. Yet despite that we should not be certain of what the dream says, unless there is some evidence to indicate that.
A living person may see his deceased relatove in his dream, advising him or telling him to do certain thing or merely talking to him or any other situation. These sometimes match with the reality. There have been some cases in which dreams matched reality and others where there is no evidence to suggest that the dreams are true. And some dreams are known to be untrue. So dreams are of three types. We must pay attention to that when dealing with news, reports and stories that have to do with the circumstances of the dead. Also it is better to not to rely on the dreams and only seek the help of the most knowledgeble person in interpreting the dreams.
And Allah knows best.