Can a living character (IE. Human NPC) become a contruct (IE. Warforged) via a soul/host transfer?

Im making a pseudo doctor character (Player or NPC), and would like to know if I can link a living characters soul to say, a vacant warforged body so that if the entity dies their soul would go into the Warforged and take it over. Is there any spells that can do anything like this in official D&D? If not, do you think something like this would be too outrageous for home-brew? The goal is for the person to retain complete autonomy, so Necromancy is prohibited.