The Flickering Lamp

I haven't told many people this because I know how it sounds, but I need to get it out. About three weeks ago I started noticing the streetlight outside my apartment flickering every night at almost the exact same time, right around 2:47am. Not a normal flicker, more like it was struggling against something, dimming slow then snapping back bright. I finally got curious enough to peek through the blinds one night and there was this shadow standing directly under it, not moving, just standing there facing my building. I froze, my whole body just locked up, and when I built up the nerve to look again maybe ten seconds later, it was just gone, no footsteps, no car, nothing, like it had never been there. I told myself I imagined it, that's just what our brains do at 3am right, but then two nights later my dog who never barks at anything started going crazy at that same window, hackles up, growling low at nothing I could see. Dogs don't do that for no reason. I checked the footage from my doorbell cam and there's a twelve second gap where the recording just cuts out completely, no error, no glitch explanation, it just picks back up like nothing happened. I've lived here two years and nothing like this has ever happened before, and I keep asking myself why now, why me, and honestly I don't have an answer, I just know I don't feel alone in my apartment anymore, even when I obviously am.