The human soul is a curious thing. Many people believe that the human soul is what ghosts essentially are. While we likely will not know what really happens to our soul until after we die, we can with relative certainty answer the question, can a ghost take your soul?
The reason that many people believe that a ghost might be able to steal a soul is that this topic gets mixed up with demonic possession. From what we currently know, a ghost cannot steal your soul from you. The reason this is believed to be the case is simply that ghosts do not have the strength, or desire to do so. It is important to remember that ghosts and demons are complete opposite beings.
The most common school of thought is that your soul will remain yours unless you give it away, or offer it up to a dark force, such as the devil. The reason one may do this is in exchange for something that the person desires, and believe they cannot obtain on their own. There is a belief that Satan can trick some people into giving their soul to him, without them even knowing it.
The other school of thought is that God is the owner of every soul, and that it is ultimately up to him to decide what should happen to it. Most people belief this, with the exception of those that believe in possession. However, possession and soul stealing are really not the same. Possession involved the soul being controlled for a certain period of time, typically until the demon can be cast out.
We do not yet understand what it is that ghosts want from us, but few believe that our souls are it. Ghosts do have the ability to draw energy from us, as well as electronic devices, in order to make themselves known, but this has nothing to do with the human soul. It is not yet understood if a ghost even realizes that it is drawing this energy.
Based on what we currently know, a ghost cannot steal your soul. If you are currently experiencing what you believe is a haunting, it is best to say prayers of protection just in case it is a demon. It is also important to educate yourself by learning all that you can about the different types of haunting, and how they may apply to you.