More Awesome Than You!

I remodeled the cemetary in Riverview by sticking an old church on it. At first I thought I would have to build around the graves already on the lot, because I would get a "cannot move object in use" error message, but then, mysteriously, I was suddenly able to move graves around. I built my new cemetery and then sent a Sim there a little after midnight to test the lot, and kept her there until she passed out from exhaustion a few sim hours later. But I never saw a ghost.

My question is: Is it possible that I somehow killed the ghosts that live there? Or am I just really unlucky in catching a ghost? I didn't delete any of the graves, so the full Riverview cemetary set should be there, plus the Remingtons. The game also still recognizes it as the cemetery; I get the negative cemetery moodlet.

Possibly but probably not relevant: I'm not currently running any mods, but I do have frameworks installed and some custom content, none of which is on that lot. I installed 1.3 but not 1.4.

So far I know, making any kind of modification in a cemetery causes the eventual ghosts saved after the first install (sims that died while you were playing),  to be transferred to the house inventary of the family who the ghosts originally belongs to. Nothing happens to the ones that were there before you started to play once they are not even real played unless you have taken one and ressurrected and killed again.
If you are missing some ghosts, take a look in the house inventary of the Sims that belongs to his family.
I don't know even if there will be any loss if you bulldoze the cemetery. Probably except for the original ghosts, all your played ghosts will be also transferred to the house inventary.

This accords with my observations too.

I built a Legacy family graveyard, and put some gravestones in it as well as some possessions of the deceased as mementoes (a guitar and a teddy bear). When I added something in Buy/Build mode, the gravestones, guitar and teddy bear ended up in the Family Inventory and the family member who was on the graveyard lot at the time got teleported home.

I don't have any ghosts that died while I was playing yet, because it was a new game.

Maybe I'm misunderstanding how ghosts work? I thought that a new game would already have some ghosts in the graveyard, and then I could add ghosts over time by moving people's tombstones/urns to the graveyard when they died in game. If I haven't "added" any ghosts, are there no ghosts, or just so few that it's not as likely I'll see any?

If there are tombstones, there are ghosts.
The more tombstones there are, the more ghosts you will see.
Not every ghost comes out every night. They come out from midnight to 6am.

The Riverview cemetary, if I'm not mistaken, does have quite a few tombstones already in it. Which means quite a few ghosts at night... Tombstones, urns, all produce the ghost of their deceased, where ever they are. NPC ghosts won't leave the lot however. So you won't see a Remington running around in the park, if her tombstone isn't in the park.

You have to wait for a while before a ghosts show up. It can take one, two days. It is more effective if you get a Sim to play guitar in the cemetery. In a way it seems to "wake up" the ghosts a little earlier. My Riverview cemetery has quite a lot of ghosts over there. I did the Play Guitar and they showed up at the first visit.

Hmm that's interesting I didn't know about the guitar. I guess also because it attracts sims to come and watch or tip.