Belief in spirits makes them real for you.
They are all in your mind but that doesn't make them less real for you. You are more powerful than any kind of spirit so if it annoys you tell it to go away. Spirits have no power over humans unless you give it to them. That's what makes you human... your power over spirits.
Most people have no contact nor dealing with spirits because they don't believe in them so the spirits can't have any power over them.