It is pretty rare. You can pay to do it or join a ball room dance club, if you can find one.
Most larger communities have ballrooms where ballroom dancing is enjoyed by movers and shakers - just like you! Find one, and have a ball! [pun intended]
The military still has formal balls with ball room dancing.
There are Mardi Gras Balls (giggle) every year.
Where I live there are lost of salsa batchata dance nights