Are there any game developers here that do voice acting for free? Just asking for future games, and I cannot pay anyone because I am unable to.

From what I've seen, some people may be willing to do it for free depending on how many lines you're asking. 

However, if you want any guarantee you'll get quality work, you'll need to pay the voice actors. Generally the only people who do work for free are amateurs. For example, I'm willing to do voice acting for free because I think it's fun, but I don't have any professional experience so you kinda get what you get

I really suggest paying or waiting to have the money to pay, at least if you want quality acting in your game. Contrary case, a bad VA can give bad reputation to your game.