Hello, I read your request and thought I may be able to offer some casual insight and/or advice.
Per your post, I garner that you were married, now are single and were alone in a large house. It sounds as if you were experiencing a sense of lonliness and your remedy was to invite others to stay with you; however, as is a regular occurrence, people take advantage of others kindness and generosity.
Your post suggests you do not know how to establish and enforce your own personal boundaries. First, one must best understand what one's own personal boundaries are. This may be easier if you closed your eyes and imagined your ideal life, in that house. If that ideal also includes hosting guests, imagine your most ideal interactions, imagine how long each guest will stay, how your guests treat you, your pets, your space, house property. After imaging your ideals, write it down in your journal or notebook. Write all of your ideals down on those pages, be as detailed as possinble. On separate pages, write down what the present reality with you there actually is and why that reality upsets you (if you know). Next, you can look at your present reality pages to compare with your future ideal reality pages, and then create a list of steps that will facilitate taking you from your present reality to your future ideal.
Finally, may I suggest that because it appears from your post that your uncomfortable present reality that prompted your post requesting help here, may stem from a personal sense of loss and lonliness; there are other ways you can address lonliness other than inviting other persons to share your home, your most intimate spaces. Perhaps you can consider increasing your out of home social activities whatever they may be, to better enahnce and enrigh your life. If you volunteer, or go to coffee, or go to public events, or play chess - consider increasing the frequency of those activities. Consider learning new activities that involve other people as well. Learning new things, enrolling in a class, can also keep your mentality active and excited and eager to go to said new events, while also providing yourself a greater sense of accomplishment. For example, I enjoy learning new languages for all of those reasons above, and by simply learning the basic greetings and a few common sayings in a new language, for example Japanese; this newly acquired knowledge feeds my mentality, knowledge, my sense of accomplishment, my confidence, and best of all - it increases my opportunities to communicate to persons I otherwise would not, ideally creating new friendship circles, increasing my sense of global community (not to mention any other professional and/or personal benefits that may come from simply learning a few new phrases in a new language).
I hope this may help you advance out of your present circumstance into your ideal. Please post of your progress and/or result to advise me how things are developing for you there.
Sincerely & Respectfully,
JP @ www.KATSCRATCH.co