How to locate ghost sim?

The MCCC mod has an option you can unhide households, and this is where the ghost goes after a sim has died. What I usually do when a sim dies and I can't find their urn/tombstone, and I just can't find them any other way I will unhide them. You'll be able to find them in the unplayed household section of the game as a playable ghost. I might be doing it the hard way but it is the only way I know how, but after I unhide them I will merge them back with the family, and then turn them back into a living sim, and then I will "kill" them off again, usually by old age (if that is what they died from before). MCCC has an option for this as well. Just make sure you save your game before doing this, in case something messes up. After the sim has died, they will go through the whole death scene, and the grim reaper will show back up again, and this time you'll also have their urn/tombstone. I would strongly recommend not letting other sims witness the death because of the negative moodlet from witnessing death.