My father's humor was totally gallows humor- he collected ballcaps from cemetary groundskeepers. He always wore his favorite while cutting grass- "Sunset Cemetary". He got a lot of odd looks from strangers.
At every visitation and funeral, he would hang out with his friend the undertaker and cut up the entire time, and they spent hours trying to figure out how, when the time came, they would rig Dad to sit up in his casket and wave bye bye to everyone!
We couldn't pass a cemetary without him saying "Everbody's dying to get in there." (groan)