There's a good chance that the same mechanism that controls one side also controls the other side and it will be dead in the same way.
It shouldn't be hard to find another switch that performs the same function. It just might not be the same size so you might have to re-work the box that the switch fits into.
You might even be able to find an exact replacement for that switch. Are there markings on the other side that you can do a Google search for?