What do I do when someone is in my PP that I don't want to be there and they keep coming back?

What do I do when someone is in my PP that I don't want to be there and they keep coming back

If the person intrudes ask them what they want and tell them that they have come in uninvited. Ask them to leave. If the intruder persists then you may need to build yourself another PP. However, if you want to invite someone in to your PP then remember to build yourself a separate entrance through which you can invite visitors.