I’m re-playing the original Sims, and I’m trying to see a haunting. But so far it’s not happening, dammit! Any tips?
IIRC, ghosts only come around at night. Best way to see one is start with a family who has a graveyard on their plot (e.g.: the Goths) and wait until nightfall.
You can also make a ghost come out of the campfire if you have a Sim with high enough Charisma tell a story.
Also, if you have the option try kicking the tombstone - makes 'em angry. 
The cutest things one of my Sims did (and she is the only one who has done it to date) was carry around a teddy bear all through childhood. It wasn’t stuck to her or anything; she just really seemed to love that teddy bear. 
All my other Sim kids usually ignore the stuffed animals and it’s always the parents that want to Talk Through it to everyone else. :rolleyes:
Anyways, she liked it so much I put it in her inventory when she went to Uni.
In regards to custom skintones, I have a tattooed one that I’m using for one of my female Sims. Her boyfriend just turned her into a werewolf, but custom skintones don’t change like they’re supposed to, so when the moon comes out she goes through the motions and growls and does the werewolf walk, but she looks completely normal. 
In Sims 2, hauntings are relatively common, as long as there is a gravestone or urn of ashes about. Some ghosts are benign and just wander around for a while, while some are vengeful, knocking things over and terrorizing the living.
Most Sim aspirations are traumatized by Ghosts (Family, Wealth, Popularity, Leisure, Romance), however, Knowledge Sims are not, in fact a ghost encounter be it benign or traumatic, counts as a positive memory to a Knowledge sim, Knowledge Sims also respond well to Vampirism/Vampires
I’d imagine a good percentage of Dopers who play TS2 have more Knowledge Aspiration Sims than the other Aspiration types, most of my Sims are Knowledge
My Aspiration prefs, most to least;
Knowledge
Leisure
Romance
Family
Wealth
Popularity