Nightclubs are hot, happening places. The atmosphere is made by the decor, the lighting, the drinks, the music and of course, the dancers. Many clubs hire dancers to get the party started and keep people dancing as well as show others how to dance in case they're inhibited.
Get your body in shape. Go to the gym and work out all the time until your body is tight and toned. Take some dance classes like hip hop, jazz and Latin to learn how to use your hips, feet and chest muscles.
Dress up and go out dancing with your friends. Make sure your hair and make-up is done and you wear clothing that shows off your body but that you'll still be able to move in. Have your friends take some photos of you before you head out. Also have them take a couple pictures of your doing your thing on the dance floor.
Look for postings online seeking dancers for their clubs. New clubs often hire dancers but sometimes older clubs will post these as well to replace old dancers. You can find these on Craig's List in the gigs or jobs section. Reply to the ad with photos of yourself (the ones your friends took of you) and your experience. If they're interested they will reply and ask you to come in for an interview.
Go to your interview dressed to kill. They will ask you several personality questions to make sure you are personable and will get along with the clients. Be friendly and approachable. Then they will often ask to see you dance so they'll turn on some music and you'll be expected to dance full out. Dance your butt off. Be sexy, interesting and fun. Everyone wants to dance when others look like they're having fun.
Get hired and then you'll basically be paid to go out dancing each night. Make sure you always look sharp and keep your body completely fit because the clothes you'll be asked to wear are revealing and they'll expect you to look your best at all times. Have fun and good luck!