Find my iPhone went off without me activating it

I am wondering why my “find my iPhone” alert went off randomly at 5am this morning. I had used it previously the night before to find my iPhone. No one else in my family has access to any of my apple devices. I was having a great sleep until it went off. Does this mean somehow someone has hacked into it or someone did it from icloud? I’m annoyed, tired, and wanting answers.