Lol how to get haunted, love the title.
Well spirits are all around us, some are stronger than others, some like traveling, others refuse to let go of a place or item [say a doll they loved in life or the scene of their death] and others might stumble across a house they like for whatever reason and choose to stay. The first spirit I ever encountered was my aunt [or cousin, can't remember, it was a distant relative anyway] my family owns a bed and breakfast and we use to go there in the summers after church when I was little. After brunch we would visit them in their living quarters. I use to talk with this old woman who sat in the rocking chair by the window. So many years later I was asking about it and I discovered that [to everyone else] I was staring at an empty chair, and who I described died well before I was even born. [but seeing spirits is normal in my family so everyone assumed it was a spirit I was looking at] She stayed because a. it was her home, and b. that was her favourite spot to sit.
You also can't really pick and choose your haunting mate [you might try putting a white candle in the window and specify 'friendly spirits welcome' is it is believed by some a white candle in the window welcomes spirits] again, I've had animal spirits and human spirits. Some kept to themself, some were friendly, and a few were tricksters [not evil, but would enjoy hiding things, randomly scaring you, or playing hide-and-seek.] Regular cleansings and specifying you wish to remove negative energies can help keep your space a positive one, but spirits are like people with their own personalities.
Communicating with spirits can be done a number of ways but practice is key [I even have to practice since my born abilities get weak over time] pendulums are one way to communicate. You need a steady hand and an understanding of how it swings for you. Daily meditation, balancing your chakras, ans energy work can all help you as they can open your clairvoyant side and help you sense energy better. [Unfortunately even with practice some people just can't connect, so you may also wish to consider technology designed for the paranormal, but research so you don't get scammed.]
You don't really need spirits to practice banishings [perhaps you have come across spirits but they can sense this other motive so they keep their distance] you can do cleansing on energy which can be practice for banishings. Banishings can also be used on people you wish to get rid of [an ex, a stalker, bully]