A GFI would be a good investment

Or isolation transformer. And carefully inspect the rubber washers that
insulate the chassis from the cabinet. If they are degraded, you can get a
shock from the metal cabinet, which is now connected to your power line.
Fortunately, they are easily replaced (check the plumbing supply department
at your local hardware store).

More info about safely operating a "hot chassis" radio can be found at
http://antiqueradio.org/safety.htm .

Phil Nelson