Phrogging is a new word, but has been going on for a long time. Think about your home, does food go missing? Do you hear noises that sound just a little too suspicious? Do you find a light on that you are sure you turned off just minutes before? What if it is someone sharing your space, hiding when you’re home and enjoying your home while you are out or asleep. 

https://www.imdb.com/title/tt6079516/?ref_=fn_al_tt_1 

https://lifehacker.com/your-guide-to-living-secretly-in-a-strangers-home-1850409226 

https://allthatsinteresting.com/phrogging/7