Firstly, I do not share this computer with anyone else who could have logged into Steam, I am not in a Steam Family, and I have not logged into someone else's Steam client. I have seen these replies online and I'm looking for something a bit less clear.

So, for context, I had an issue with some file corruption while downloading a new game which bricked my external hard drive, and so have been dealing with my built in hard drive by reinstalling games that were on the external drive that I wanted to play. That was when I noticed that a game I did not own was in my Steam Library, Total War Warhammer 3. I did not buy Total War Warhammer 3, yet it is in my Steam Library and it says "Install" rather than "Purchase" like I've seen in other threads. I wanted to get in touch with Steam Support to let them know about my dilemma, since it is not giving me the option to remove it from my library, and I don't want to get into any trouble with Steam since I have not bought the game.

The TL;DR is, a game I did not buy appeared in my Steam Library, and I don't know what issue I should be submitting it as through the support system. Any ideas or suggestions would be helpful.