Up late can’t sleep, here on my own with my kids so quite alert to any noises. Heard something outside looked out the window and saw a large man using his iPhone torch and entering next door through the downstairs window. Freaked out and phoned 999 to report what I thought was a break in. Turns out my neighbour forgot his key 
now I feel like a dick, but wouldn’t have forgiven myself if it was someone breaking in and I didn’t do anything. Police turned up and banged on their door, not looking forward to seeing the neighbours in the morning now!