What should I do in this situation , Please read below?

My ex and my 19 year old son still live with me , and every time my ex argues with my son over the dumbest things , my ex tries to drag me into it. I will immediately try to defuse the confrontation between them , but they both scream and attack each other and say vicious things to each other They both suffer from ADHD and say some crazy shit to each other. I will tell my son to watch what he says to his mom and tell him do not disrespect your Mom that way, but he still defends himself because she keeps saying vicious things to him basically getting in the last punch , to the point I am stuck in the middle , because she starts attacking me for not beating him up over it? I will yell at him and tell him to shut his mouth , but she keeps attacking him and getting him fired up , so I tell her to shut her mouth as well and go in the other room. Why does my ex think I should beat him up when she is clearly wrong as well? I told the both of them if it doesn’t stop then the both of them need to leave the house or I am calling the cops to have them both escorted out of here. . My ex and son both have love and hate towards each other , My ex acts like I am supposed to kick his ass and hit him when clearly she is in the wrong. I refuse to beat up my son because my son does nothing wrong to me , he knows his Mom is psychotic and he understands why I left her ass because the girl is mentally insane and needs serious mental help. Am I wrong for not beating up my son? I was raised by an abusive alcoholic father that beat me and my brothers up , I refuse to be that kind of parent to my kids’ unless they did something completely dumb and stupid , I am not going to beat up my son for defending himself from his psychotic mother that doesn’t know when to stop attacking , now if he laid his fingers on her , then yes I would attack , but words , it’s not worth it? Am I wrong?
What should I do in this situation , Please read below?
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