You’re not alone - attachments are a common problem and there’s many ways to get rid of them.
For human ghosts I’d try talking to them first and persuade them it’s ok to go “to the other side” and have them go on their own. Failing that ordering them to leave can also work - you’re dealing with a human personality so, like people some are more entitled than others must most will leave peacefully when asked to.
We have a bunch of options for banishing or attacking them as needed. With the really tough ones that hide, hang on and punish you for pushing them away, the activity escalates until it’s no more Mr. Nice Guy nd you directly attack them. Then they always go. You probably don’t have that kind but you have all the tools available for any size problem. 