There’s an old, old story about a butler who worked in an old, old house.

Each day, he walked past a room whose doorknob he once tried, only to find it was locked. The more he passed that door, the more he wondered what was behind it. So one day, he bent down and looked through the keyhole.

What he saw was another eye looking back at him.

That’s where the story ends, so nobody knows what happened next ... although I recently passed up a chance to find out.

People ask me if I believe in ghosts, and I say, “Why not? They seem to believe in me.” That’s why Spangler’s Spring at Gettysburg’s battlefield draws me the same way shopping malls once drew my parents. Whoever is there knows me, and I must know them. I always leave a cigar for them.

A small stone cabin near the woods is said to be the abode of The Woman in White. It dates from after the Civil War, but people often see her there. She’s said to have killed herself after hearing that her lover was killed in the battle.

One night, my buddy Gary and I saw lights in its window from a good 50 yards away. We went to investigate and found the building surrounded by a zone of indescribable cold. It began as abruptly as a brick wall, but went away when we backed off two or three steps.

“Cold spots” are common in haunted places, and it’s an unnatural cold that starts from inside you. It’s especially noticeable when you’re wearing several layers of clothes that normal cold would take time to penetrate.

We found cold spots everywhere, but there were other areas that were far warmer than they should have been in late November. Once when we stood facing each other, Gary was cold with goosebumps on his left side and I was cold with goosebumps on my right — but both of us were warm on the opposite side. There was no wind.

“They’re talking to us,” Gary said. “They’re telling us they’re here, but they know us and we have nothing to be afraid of.”

The sudden intensity of the cold zone around the stone building was menacing.

“Hey, brother,” said Gary, “They’re telling us they can’t help us if we go any closer.” We went closer, anyway. Brave us.

When I’d looked through the same window during the daytime, I saw only an inside wall a few feet away. Our buddy Mark took a picture through it one night, and when developed it showed The Woman in White unmistakably looking back at him.

Gary and I avoided looking in the window at close range. We both remembered that photo and reasoned that, “I don’t want my buddy to have to drag my heart-attacked dead (beast of burden) back to the car!”

When we returned to the spot where we saw lights in the window, we could no longer see the building — even though it had been easily visible a few minutes earlier.

It almost seemed to have disappeared, but we didn’t feel like going back to find out. Time apparently means nothing at Spangler’s Spring, and other things we’ve seen there have disappeared. An Indian grave I discovered on my first visit to the place hasn’t been there since.

Then we noticed several other lights meandering slowly toward us through the forest. Just as they reached the edge of the woods 10 yards away, a car came by with its headlights on, and they vanished. We waited, but they never returned.

A few minutes later, the night air was torn by what Gary and I recognized as volley fire from muskets — rapid fire, almost like that from a Gatling gun, but with an irregular cadence. This lasted for a minute or more before fading away, and there were so many shots we couldn’t count them.

They were war shots, too; black powder makes a much different sound when it pushes lead down the barrel than it does when touched off as blanks for the benefit of tourists.

It came from across a ridge less than 100 yards away at Culp’s Hill, where a real firefight started that same time of night 145 years ago. The lights we saw in the woods — and a couple of dark shadows that Gary caught out of the corner of his eye — had been headed that way.

A gray shadow emerged from behind a tree no more than 20 yards from me and sped across the clearing toward the woods. I watched it the whole way and decided that while the soldiers must have been going to the battle, The Woman in White was fleeing from it.

Sitting on my back porch at home a few nights later, I wondered what would have happened if I’d looked into that window from up close. My distant glimpse of The Woman in White reminded me all too well of someone else I saw — and was close enough to actually touch with my hand — 35 years ago.

That experience is the reason I know that when your hair stands on end, it starts at the nape of your neck and works its way up.

And I was a lot younger back then.

Shuddering, I glanced up into the sky and whispered, “Thank you, Lord, for sparing me from such a thing.” At that moment, the thick clouds parted to reveal a bright star in the very place I was looking. It gleamed for a moment, then vanished. I could almost hear the voice say, “I am here, my child. You’re welcome.”

Our friends warned us we were going beyond their ability to protect us, and it was no surprise that they would do such a thing; they once kept me from taking a nasty fall. (Gary said he looked down and saw me stretched out almost horizontally, hands waving and hanging in mid-air with only one foot on the ground and my face about eight inches from the dirt.)

However, there was still one hand that could reach out to shield us ... as it’s done for me so many times. Both good and evil must be found in whatever world it is that lies next to ours. If you believe in one, you must believe in the other. Just beware of the dark side.

It’s likely that men from both sides of my family have bled into the same ground I’ve now walked upon. It may be they who try so hard to speak to me.

When some day I am able to hear their voices, I may find that a part of me is already there with them.