I live alone.
I have window film on the lower windows in my living room because I'm over looked by a road.
Sitting in the living room, lights on, curtains not drawn, I suddenly saw the silhouette of a head/body through the window film. They would have to have been in the front garden to be that close to the window.
Whoever it was was definitely trying to see in the window because the silhouette went backwards and forwards. It was really scary! I was so freaked out I sneaked over and quickly drew the curtains.
Really really weird and now I'm scared to go to bed!