From my experience with Irish spirits and THEIR houses, can be scary for the people who never encountered anything before.
First thing first, do not use any religious items such as holy water or a priest’s blessing without to know who is keeping the house. Most of the time it’s an old house or an estate house. Most of the time it’s a being from religious beliefs. They will get offended. Let me explain more.
When we pass away, we first leave our body and then we are to go to another “realm”. I use the word realm, I could say the light, a door, but I won’t call it heaven because there is no hell. But religious people do believe that while alive and from the old thinking. They fear so much, they believe in sins and guilt, they blame themselves for been abused too. So, they do not cross by fear they would be harshly judge by what they were taught.
Some people who did not realize they left their bodies, they stay in-between. They either stay where they passed, looking for help or they go back where they felt secure or to their belong, their home. Occasionally, some will pick and follow a stranger.
Nothing may happen in the house for years. As strange things and feelings can occur not long after their passing. They are attached to their human lives, thinkings, principles and materialistic. Their homes hold their energies of their memories, pasts and emotions. They believe entitled to have their say to anything concerning their properties or anything happening under their roof.
If you are a descendant they may come to enforce their beliefs. If you are a stranger, they will be unpredictable.
Don’t let the movies playing trick with your mind. Keep calm and respectful. Do not involved anything that will keep them rooted.
Why not religious tools? Exactly because most of the time it’s what keep them from crossing. They are scared, makes energies unbalanced even more, and decrease the livings energies. It becomes a circle of negativity nurture by fear from both living and spirits.
These days, I heard more people having troubles with their houses. Some of you don’t know yet having the abilities to help them. That doesn’t mean you have to do anything hoodo vodoo. Sometimes just talking to them, comforting them and reassure them that it’s not their fault and everything will be better for then to go on the over side, can be enough. Some may need more assistance, and you may look for a medium or a shaman. But again, let’s aside and away from what they know, religion. Some resistant may stay away for the while and come back once the priest is gone.
You must realize those souls stuck in-between are like us when we haven’t done our inner work. They have been told what to think and what to believe, bringing themselves down when they shouldn’t have. Their conviction holds them back like we do.
On the estates, can be more into their stories out of the religious beliefs and they can be angrier for injustice and not seeing where to cross. A lot of estates were built on or close by mass burials.
Imagine yourself seeing everything and everyone but no one hear you or see you. You would attempt anything to get the attention for help. But the livings do not comprehend this and limit themselves to what they only physically see and hear through their own logic. They do not intend to harm us they simply can manipulate through energy, something that we all can but programmed to suppress it.

My advice if you have no idea what to do, especially when you thought this was just rubbish or you were crazy. It is important to keep your mind and body healthy, rested and peaceful. More you get angry, frustrated, confused, restless and exhausted more you bring negativity energy to feed on. It’s like opening a door within us, unconsciously, and allowing them to show you, to tell you. More you keep yourself grounded less trouble it will be. Use smudge to keep the energies balance in the house and around you regularly. Get someone to help them until you are able yourself.
Don’t be afraid of them, they are just like us.