You've chosen a really bizarre subreddit for this story. Lets Not Meet is for stories about stalkers/creepers/kidnappings/etc... The main focus of LNM stories is the fact that there is some frightening encounter with a real person. Scary knocking noises don't exactly fall under this subreddit unless you believe a person is following you around everywhere you go, attempting to frighten you. From what you've told us, I think that is VERY unlikely.

I think either you know that these noises are inappropriate for this subreddit (because there's no spooky bad guy involved) and you've chosen to post your story anyway, or you genuinely believe someone is stalking you just to spook you with weird sounds. Based on the information we have here, believing someone is intentionally doing that to you would be insane, and I would recommend that you call a doctor, not the police.

Do you have any LEGITIMATE reason to believe someone is actually doing this to you intentionally, or are you just posting this story for shits and giggles? I gotta know, fam.