While serving aboard the USS Aylwin (FF1081) the ship went into the shipyards in Portsmouth, Virginia. Metro Machine Corp was where the ship was docked for its refit/upkeep period. While there the crew was stationed on the second floor of the main building sleeping/living 'barracks style'.
I was standing the mid-watch 0000-0400 (midnight-4am) and while making rounds through the crews sleeping area I saw a shadow out of the corner of my eye. Thinking I had someone 'sneaking' around I started looking for whoever was out of bed.
I would have been less concerned had this 'person' been moving towards the bathroom/showers, but the 'shadow' was moving around randomly about the crews sleeping area and I needed to make sure someone was not trying to steal anything.
After 20 minutes of following this 'shadow' around I stopped and watched and listened... The 'shadow' was making no sound as it moved and as I looked down the aisle I was on, this 'shadow' stepped away from the wall, and I realized that I had not been following a person, but a spirit, and this 'shadow' spirit proved me right by walking right through the wall.
I didn't say anything to anybody and after duty turnover I went to look at the section of wall the spirit had walked through. You could see where a doorway had been bricked over, and if looked at from the outside there were the remains of an old fire escape.
I asked around the 'yard birds' (shipyard workers) over the following days and they had lots of stories, from all over the shipyard, but two different gentlemen remembered a poor man who had exited one of the fire escape doors and then had slipped on the ice covered stairs, falling down from them and breaking his neck.
They both pointed out the same fire escape that came from the bricked over door. This door had not been covered due to the accident, but due to a remodelling of the second floor from repair shops to a sleeping/living area for ships crews. (It's better than a barracks barge...)
When this had been done the emergency exits had been moved to meet the new fire-code requirements.
I'm not sure if this shipyard is still open or not, but if you believe all the stories from the 'yard workers' there were lots of ghosts that roamed over this shipyard.