1.What do our soul looks like? Is it possible that a dead person who has unfulfilled desires wander here and there.
2. Can sorcery kill some one from a distance without touching or seeing.
The soul is that part of us which is a part of God. It is formless and invisible, so it does not look like anything. The soul, when taking human form (reincarnating), is contained with the physical, astral, and causal bodies.
The physical body is easily observable and tangible. Just look in a mirror or touch your arm. The astral body is sometimes seen by people or it may be photographed by special machines. It is made of light and is sometimes called an aura. The causal body has no form — it is the thought or idea of a person as an individual.
Yes, it is possible that a person who is dead may still retain his or her astral body on this earth-plane, due, as you say, most likely to unfulfilled desires. Yogananda calls these beings “tramp souls,” (most people call them ghosts) and strongly cautions us against trying to contact them. They are lost and confused, but they will eventually figure things out and make their way into more beneficial lifetimes.
People who join themselves together with the dark forces, which do exist in this world, and practice things like sorcery, can cause a great deal of trouble for themselves or for weak-minded people — perhaps causing them to be susceptible to disease, accident, or even death. But if you are strong in yourself, especially spiritually, but also in your astral (energy) body — keeping your very aura strong, praying always for God’s presence to be there in your life, then negative forces have little or no power to bother you.