Make Love To a Ghost-Fool joke

A visiting professor at the University of Alabama is giving a seminar on the supernatural. 
To get a feel for his audience, he asks, "How many people here believe in ghosts?" 
About 90 students raise their hands. 
"Well, that's a good start. Out of those of you who believe in ghosts, do any of you think you've ever seen a ghost?" 
About 40 students raise their hands. 
"That's really good. I'm glad you take this seriously. Has anyone here ever talked to a ghost?" 
Fifteen students raise their hands. 
"That's a great response. Has anyone here ever touched a ghost?" 
Three students raise their hands. 
"That's fantastic. But let me ask you one question further: Have any of you ever made love to a ghost?" 
One student in the back raises his hand. The professor is astonished. He takes off his glasses, takes a step back, and says, "Son, all the years I've been giving this lecture, no one has ever claimed to have slept with a ghost. You've got to come up here and tell us about your experience."
The redneck student (remember, this is Alabama) replies with a nod and begins to make his way up to the podium. 
The professor says, "Well, tell us what it's like to have sex with a host." 
The student replies, "Ghost!? I thought you said 'goats.'"