A man in the property always bothers me. Their property has a key card to my room. I'm worried that when I go to work, he will come into my room and secretly install a camera or something.

First of all, seriously show him that you are not interested in him; Secondly, take care of valuables or personal belongings in your room;

Moreover, you can go home from time to time to scare him; Also, you can take photos of your own doors and things (make a mark that others can't easily detect), or install a camera at home directly, so that you can collect evidence;