I'm not saying to do this, but some people have used the black wire as hot for one device (light or fan), white wire for hot for the other device, and ground wire as neutral (with a jacket on it). The light and fan would not be grounded but the switch would be. Again, not recommending because it would not be to code, but it works and shouldn't be a safety issue - there are lots of old houses with ungrounded light fixtures - table lamps aren't grounded either.