I don't know how old this joke is but it's good.
This starts like any other wish joke, A white guy walks along the beach and what do you know a lamp. He rubs it and out pops 2 genies who happened to be blonde. They tell him to make 3 wishes and the next day they will come true. He goes home and when he wakes up the next day. He is surprised to find that he is in a huge mansion. He is like sweet. Throughout the house is huge amounts of money. He is just starting to enjoy the place when the doorbell rings. When he answers there are 2 people dressed in KKK uniforms. Before he can do anything they grab him tape his mouth and proceed to tie a rope around a tree, stick his head in a noose and hang him. They take off there hoods to reveal the 2 blonde genies.
One says to the other "I can understand him wanting a mansion and I can understand him wanting to be rich, but for the life of me I can't understand why he wanted to be hung like a black man."