How You KnowHey. I'm just going to tell you a few symptoms. These can really help.
So, supernatural connections, can cause a few things. It can cause Personality Disorder, which means you and another person (usually a monster, like the Devil or some sort of evil source) combine and switch between personalities. I had this for about 3 years. It was actually an enemy of mine, who always visited the Cemetery. This disease is a little biased, but it can happen. Eye color changes, different personalities, and features that are unlikely for you are only a few things that describe what could happen to you with this disorder.
Another type of experience only happens in the night. It can only be summoned by lifelong objects, such as a stuffed animal, or a doll. The part about glowing eyes....that's fake. It turns out, they come from whoever had it first. If your parents have any of the following clues that could be proof that you should keep any objects like that locked up....I had to. (Memory Loss *and this is not normal for parents if they literally can't remember*, Fast Growing Hair, Red Hair *usually scientists keep this as a genetic response to sexual reproduction. it really isn't*)
These are only a few ways. Whether you really are scared you have Personality Orders, or Ghost Sightings, or just reading this for your own personal enjoyment, don't let this get to you. It's not likely this happens to anyone.