When a person dies, sometimes he/she is not always willing to leave the Earth for the next incarnation. There are many reasons why they do this. Mostly it’s because they have some “unfinished business” on Earth or they simply don’t realize they are dead. They think they “have to finish something” before they leave. But how you can finish something when you don’t have a physical body? These souls stay on Earth and because they need energy resources they start to take it from humans. It can be very debilitating for those involved, mostly family members from my experience. Also, drug, alcohol or other abusive substances users are usually victims of annexed souls as these look for someone weak and manipulable.