I'm a security guard that works for a firm which subcontracts with nation/state parks.
Most of what I do is just monitor parks, making sure that no one sneaks in during the evening hours or that there are no wild animals on the loose. I am not allowed to share any pictures of my nightly routine, due to privacy concerns.

>Sent to a place called "Preston Park" in Western PA
>Once owned by a chemist and his wife
>All their original stuff is still there, including the husband's equipment, which is monitored 24/7
>Nice lake out front with an abundance of ducks who come out during the evening hours
>Turn back around to the house to see a couple staring back at me from the back window, which clearly resemble an elderly man and his wife
>Run yelling, "hey you two, this are is off limits!" with no avail
>As I approach the house the two disappear like shadows being dragged away from light
>Still shaken to this day

The whole place is now unnerving as shit. I have heard people give similar stories during the day too. Also, don't get lost in the woods like I did. DO NOT get lost in the woods on a dark night.