Yeah, check it out with a locksmith.
Oh, and Shagnasty, that’s a beautiful house you have there. I’m with boytyperanma – drilling a hole and using a camera to see what’s in there would probably be the least invasive thing to do. It’s hard to say why they would have closed off a closet that is similar to one found in the other rooms, but maybe you could learn the answer.
Shag, leave the space alone! This is an ancient house that might contain ancient secrets. Or ancient evil. Even drilling a hole might release some eldritch horror.
Wait, you said your ex-wife lives in the house now?
Never mind.
My brother found a floor safe. We drilled a hole (with much effort) and shoved a see-snake in there. Empty. He poured concrete over it.
Shagnasty, could you look down into the secret space from the attic? Drill a hole in the ceiling and peer inside? That way you don’t wreck any of your lovely living space.
< oops edit, I did not see the part about the closet above it. Never mind. Is there a basement? >
The company I work for has had many safes punched over my years here. Most have been empty, some have contained dull things like old cards and letters, a couple had interesting things like silverware and tintypes. And one contained evidence of a past crime and another contained an assortment of munitions the original owner had brought back from WW I most likely.
I would punch it or have it punched before I moved in. Better to find dust-bunnies than risk a go-boom or long explanation later.
I’m with the majority.
Sure, it’s probably empty, but the what-ifs would drive me nuts.
And, like DCnDC mentioned, the safe itself probably has some value. If you can get it open without damaging it and then redo the lock, at the very least you’ve got yourself a cool old safe that you can now use or sell.
Shagnasty, I have thoroughly convinced myself that there are human remains in your house.
You are SO missing an opportunity here. Remove the bookshelf, then the wall - almost certainly nothing there but an old closet space or possibly an unfinished space. If its unfinished, finish it. Install lights, etc. Don’t put the wall back as-is; install a false wall on hinges, with the bookshelf covering it. Now you can close it and it looks like it did prior to the modifications. Presto! Custom hidden room.
Sometimes safes do contain valuables. An ex colleague was involved in closing down a site back in the very early 1980s. this included getting rid of a large safe, to which nobody could find the key and hadn’t been opened for years. It being a defence-industry site, that wasn’t a problem for long. 
There was £90K inside. :eek:
I picked other because my answer would lie between choices one and two. I’d be content with the first one, but then over time I’d want to TRY to open the safe.
I’d have no real desire to open it up, and I’d leave it be until I had some free time and got bored. Then I might try to open up the safe- not so much for the fact of finding out what’s in it, but to see if i could try to open the safe if it makes sense. Like if it’s an old fashioned type of safe and all- could I crack it open, or would I need a drill, etc… The childish fantasy of being a Safe-cracker or Ace Cat Burgler or something like that.
Once I went on a call to open a safe at a recently widowed woman’s basement. The safe belonged to her husband and she had no idea what was in it. A coworker and I headed over there and worked on it for a while, eventually managing to manipulate the mechanism open; anyway, we opened the door a crack and notified the woman that we had succeeded(we were taught not to look inside). We were packing up our gear when she opened up the door and gasped, then ran out of the room. Intrigued, my colleague and I turned and looked inside the safe-- it was full of sex toys, bondage gear, and porn. Guess that’s why they taught us not to look.
This is what I’d do. Even if I was 99% sure it was empty, the challenge of actually cracking a safe would be too much to pass up. I’d probably keep at it until I got it though, because hiring a professional would be and admission of defeat.
Porn lair!
My dad’s house (1927) has a tiny door in the stairwell. It’s painted shut, and not too easy to get into, as it’s on the wall directly in front of you as you’re going down the stairs. To operate it smoothly, you need to be eight feet tall or jury-rig a ladder at an extremely unsafe angle. It would be a tight squeeze for a human, easy for an eldritch horror.
I missed this the first time I went through the thread. I have a sawzall, where do I meet you?
No really. Patching a hole in a wall is easy. We did some rewiring to interconnect all our fire alarms, so we had to cut several softball sized holes in the wall. Patched 'em and painted. You’d never know the hole had ever been there.
Go look in the hidey-hole and report back to us!
Could that be for cleaning out a chimney or something? My fiancee’s house growing up had a similar door. It was for milkman deliveries. She used to climb through it. But then the house was renovated and the way the stairs got changed around, the door is now in a weird place (and bricked shut).
I’d be mildly interested in the safe, but I wouldn’t have to know. If I could get it opened for cheap, I might try it.
Bah! Forget the safe, I wanna know about the body in Shag’s wall.
Lathe and Plaster is harder to patch than Drywall.
I’d have that sucker open before the ink was dry on the mortgage papers.
Shagnasty, you guys are nuts. Your ex’s family’s wealthy, right? You could obviously have fixed the floor!
Good guess, but I doubt it. I can’t remember where the chimney exits, but to come from the fireplace it would have to take a 12’ horizontal detour. Are chimneys always straight? I have no idea. Its a plain wood door with a latch, not as industrial as I’ve seen attached to a chimney. I will have to crack it open next time I’m down. It hasn’t been opened in the few years they’ve been there, and the previous owner had mobility issues and I doubt she personally did anything with it. Must not be too crucial.
Mr. Shagnasty, tear down this wall!