Negative spirit?

Alright, I'll try to cut to the chase. 1 day after I tried to get into contact with my spirit guide about 3 in the morning my mom says she heard a banging on my wall. Like someone was literally taking the palm of there hand and slamming it into my wall. She comes in here and I'm alseep but my dog is on the ground looking at the ceiling. It's weird how I didn't wake up because I'm a light sleeper. The next night It happened again but her boyfriend woke up and heard it also. It happened again last night and its really freaking my mom out. I need to get rid of it asap. It could be someone in my attic but that is highly impossible as my friends went up there to unlock my door recently. She also said she called the cops and got them to check the attic when It happened but I was gone for the 2nd time it happened. So my only conclusion is that I have attracted a negative spirit although I did visualize my self with light around me and I said a prayer to ask for protection. How can I get rid of this?

[Thunder Bow]

Use Cedar, burn a small twig, put some around the house. Sometimes a stronger protection is needed, more than just light.