I am christian, and even though I don't "believe" in ghosts per se, I am open to the thought. I've always liked watching ghost hunting shows on TV, and though I always thought they were a bit goofy, I thought, what if?
I have two stories, one experienced by a family friend, and another that my parents encountered. The family friends story is first.
He lives on the Wilderness battlefield edge, and every night, especially early summer nights, he will smell tobacco, coffee and campfire smoke. In the daytime, he will smell gunpowder, especially during the battles anniversary. My dad had permission to metal detect his yard, but because of his work shift, he wasn't able to in the daytime. So one night, my dad is in his front yard swinging his detector, while his friend was on the porch watching. My dag dug up a fired bullet, and as he did, he got cold chills, and felt like he was being watched, opposite the front porch area. He never went back at night again.
Here's another one.
When my mom and dad got married, they visited Gettysburg a lot. They loved walking the battlefield early in the morning. Once, they arrived at the crack of dawn. It was a crystal clear, quiet summer morning. They were walking beside Devils Den. Then all of a sudden, a thick mist rolled in, and they heard very clearly, reveille being played on the drums, and a soft bugle call in the distance. They walked towards the sound, as it kept playing, and the sound never got louder, or quieter. They followed the sounds of the drums for about five minutes, before they stopped, faded away, and the mists rolled back. They searched that area for hours, looking for a prankster drum player, and even went to the office, finding nothing.