My wife watched a Lifetime movie that was like this. Can't believe she watched that channel - she's now moved on to Hallmark.
Anyway it was about a young married couple who hired a live-in nanny to take care of their kids. It didn't work out and they fired her but she wouldn't leave.
She filed against them in court saying she lived there for a certain amount of time (don't remember what it was) and had rights and they couldn't make her leave.
She had guys over all the time and had parties in her room and it was a real nightmare for the young couple. Don't remember the details but they eventually got her out.
Can't believe I watched this with her. Never again. lol
Hope it all works out for you in the end.