Dreaming of a deceased is usually a warning that something unpleasant is about to happen. If in the dream you speak with the deceased, even though you do not remember the dialogue, it may be warning you to take care of enmities, or more likely, to monitor your own actions, behavior and errors. In spiritualism it states that this type of dream is actually a direct communication with the dead. If the person who appears in the dream is a known enemy, the risk is greater, but if you dont know the deceased, then you should meditate on the case. For example, if the deceased is a beloved family member (parent, sibling, etc.) then the approach can be interpreted as a warning to protect the dreamer of possible unpleasant situations, but it can also be a visit or loving encounter between parents and children, in which case the dreamer must be thankful. Obviously what has been said changes the meaning, if the dreamer remembers the dialogue with the deceased.
Read more about dreaming of Deceased in other dream meanings interpretations.