There are a whole host of websites out there dedicated to connecting singers with music makers. Websites like SoundBetter.com can help you find vocalists online with review systems, resumes, samples and more. And if you don't like SoundBetter, there are plenty more besides. Y
ou can find EDM vocalists for hire all over the internet with a simple and quick google search. Even sites like Youtube and SoundCloud can be great resources for finding fantastic new talent. The covers that the most views might be an indicator, but you should also take a look at the lesser known channels to see if you can find a hidden gem. And the bonus of this is, it is free!
Trying to find vocalists in your area can be a bit of a toughie but again, you can use the internet to great effect here. There will be adds on Craigslist and other sites where people post positions and jobs that they are looking for.