I keep aging off, but have downloaded ghosts from the Gallery.
Currently I have about 6 ghosts in the pc version of the game, and two ghosts and two ghost dogs in my PS4 version of the game.
For PC version I have an adult ghost that I moved in with teens to give them some extra money. The teens don't like her too much yet. In the same save, I have two Frozen Elsa ghosts, a Frozen Anna ghost, a ghost Rapunzel, and a ghost Merida living in a graveyard that I had to add a few things to, but I wanted ghosts on a graveyard.
For my PS4 version, one of my houses I moved in a ghost Sim, and two ghost dogs. My plan is to move in a sim later to live with her, but right now I want to focus on the ghost before moving any other Sims in. For my second ghost, it is a ghost Elsa from Frozen who I moved into a haunted house that had a witch Elsa, a normal Anna, an Elsa from the Gallery that gave birth to a girl I named Astrid, and finally a mixed breed dog. The ghost Elsa is to add a bit more spooky stuff to a haunted house.