Sounds like a speed camera
I`ve never experienced anything which is in one way a shame and in another a relief! Well, apart from once at my friends house when three of us clearly heard someone (we thought it was his daughter) get out of bed and walk across the room directly above us. She was fast asleep in the back room and, before anyone says it, it was most definitely NOT the house settling.
Been in some pretty remote places alone as well as plenty of steeped-in-history lakes but apart from a couple of nervous moments caused more by desolation, auto suggestion or a fast atmospheric change, I have yet to be convinced on a personal level.
Too many stories, too many reports for the paranormal to be dismissed as baloney. Maybe I`m just not the `receptive` sort and will never experience anything first hand.