My friend Maryna has lately had a new "ghostie" at her premises. I'm not sure if she is happy to keep this being around or not, so it would be presumptuous of me to rush in with advice on removing it. However, I do know a method, so I'm sharing it here for anyone who may have need of one.
Actually I know several, but this one is particularly good because it also removes the reasons for the entity to be in your space – therefore, once gone they are liable to stay gone. It was taught to me many years ago by my great friend and teacher Jenette Youngman, who called it Karmic Completion, and it has many applications. I love it because it involves treating all beings with respect, unlike some forms of exorcism and space clearing which are cruel. To become adept takes time and training, but the following is a simple version that works for this kind of situation.
Ground, centre and protect yourself, then go into meditation and send lots of love to your "visitor". (All beings are children of God and are worthy of unconditional love for that reason if no other.) Ask what name you may call them and if there is anything they need to communicate. If you have not been aware of this presence until recently, perhaps they're not just stuck on this plane but have some other reason for visiting. If you can get them complete on that, they may then be ready and willing to go to their future destination / destiny. If stuck, there would be a reason for that too, so the same applies
It is enough just to hear what they have to say, acknowledge each utterance with "thank you" (for the communication, regardless of what it is) and keep asking every so often, "Are you now complete on this issue and ready to take the path of love to your future evolution?" until they say they are. Don't get involved in making promises or carrying out any actions they may request; keep it on the level of dialogue. You’re in charge! You have the right to say who or what may enter your space.
If the being has something to communicate to someone other than yourself, just ask them what it is and have them say it to you until complete. Keep asking, "Is there anything more you need to say to this person in order to be complete on this issue?"
You can create a path of love with visualisation and intention. Some people see it as white light. However you see it, it's important to identify it as a path of love. When they declare themselves ready, invite them onto it, and watch them along it until they disappear in the distance. THEN DISSOLVE THE PATH! (You don't want any uninvited entities coming along it.)
If they get stuck on the path, you can ask, "Is there anything still incomplete for you?" If it's fear paralysing them, ask if they would like an angel to accompany them, then have them call for an angel and let you know when one has come. I have never known them not to agree to calling for an angel, nor an angel failing to appear and accompany them the rest of the way.
Don't dwell too much on this matter thereafter; let it be complete for you too.
Of course, if the visitor turned out to be a guide or angel, you might not want to send them away. But be on the safe side – some make claims that are untrue. You can always call guides or angels to you later in case of need and they will happily come, even if you have previously sent them away. Also, check how you feel in their presence. Clear and empowered is probably a good sign. You can send love to them and see what the response is. Anything that is aligned with love will love you right back and that should be felt unmistakeably. Any other response is grounds for sending them away.
(This process can also be used to clear any disempowering aspects of one's own psyche.)