So in cases like these, the only way to get the unwanted guest to leave is to negotiate this with your fellow resident and if that doesn't work out then I am stuck with that guest and nothing more can be done?
What does "cases like these" mean? I still haven't seen a reasonably complete set of facts.
Is there any reason why no one suggested getting a restraining order against a person then calling police and claiming that the person violated it?
I can't speak for anyone else, but I haven't suggested that because you haven't provided any facts that would justify the issuance of a restraining order.
Just wanted to know what rights do people typically have in cases where they do not want someone in their house yet their fellow resident does.
Well...that's a new fact that you're just now sharing for the first time in the
33rd post in the thread. Sigh....
Creating a list of "rights . . . people . . . have" would be utterly pointless. If Person A and Person B live in the same residence (and both are legal adults and neither is the landlord of the other), then Person A doesn't have any legal right to regulate whom Person B has as a guest in the shared home. Of course, if Person A has grounds to obtain and actually does obtain a restraining order, then that would change the conclusion.