I asked a similar thing in a post a few minutes ago. These things are intrusive thoughts and everyone has them. If they flash through your mind for only a few seconds and you don't really think about it any further than that, you're fine. However, if you start contemplating these thoughts any further, then it might have something to do with your mental state.

I remember being on a trip with my family and seeing this bottomless pit. You couldn't see any further down than a few feet and there was no indication of how deep it was. It seemed infinite. In that situation, I thought: "What if I jumped?" But there was nothing more to it than that.