There was a forest at the edge of the town where you grew up. No one ever went inside, not even you. It wasn't that you were told not to, there was just this presence around it, like it was forbidden ground. It was just ignored and left alone. No one ever even talked about it.
You always thought it was pretty, though, with its tall dark trees and ominous presence. As an adult, you purchased a house that bordered the edge of the forest. You didn't have many neighbors, so it was quiet and peaceful.
One night, as you're sitting on your back porch enjoying the cool night air, you notice movement in the trees. Looking closer, you make out a shape walking slowly through the outermost edge of the forest. Shimmering silver, a lithe, elven person slips out of the forest and into the moonlight. They stop dead when they see you, freezing in place with wide eyes. Then, as quickly as they arrived, they disappear back into the trees, fleeing your gaze.