My suitemate and I don’t share a room, but we share a bathroom. I have found her hair (which is VERY different from mine) all over my stuff in my room and in my bathroom. I even found it inside of my makeup box in my room. I don’t know what to do.
If you go the camera route make sure it doesn’t record audio and insure your local laws and school rules don’t explicitly ban them (lots of housing agreements do)