Are exorcisms real?

Exorcisms are real because if they weren't how do you explain the paranormal activitys or objects such as ghosts? Or how can someone just get mental illness and start sractching themselves to were blood comes from their body and their harming others? Why would someone say the six demons names that are written in the bible out in a diffirent voice? I mean if there are angels who do good then there sure must be demons who do bad and try to invoke the spirit to do bad things. Without evil there is no good, and without good there can be no evil!

Possession by demons is not real, so exorcisms to drive out the non-existent demons are also not real.