Will an old 240 volt system run a new 240 volt ballast?

I live in a house that was built in the 50's and the 240 volt is a 3 wire with 2 hot leads plus a ground. There is no neutral or white wire can I still run a 240 ballast off this if I set up the adapter? If not what can I do to utilize this power short of rewire which is not an option as this is a rental.

You should be able to plug a 240v 3 prong ballast into a 3 prong 240v outlet no problem. You should not need an adaptor. The ground is your neutral. The ground and neutral usually connect in your panel anyways. You are lucky to have a ground wire at all being built in the 50's.