Suppose you have an RF generator feeding a vacuum system with argon ionized by that RF. With the tuner you see the VSWR is very good. That is version A, no ground or poor ground. Version B is the same thing, the container is stainless steel half inch thick to hold the vacuum. But in this case there is a very good close ground, where the frequency is one of the medical frequencies, in this case 13.56 Mhz. Power, 500 to 900 watts. If condition B has a ground within 1/4 wavelength, about 4 odd meters to a literal ground rod 8 feet deep in damp soil. Would there be less RF radiation from the stainless steel case vs one where the case is poorly grounded? Is that the point of grounding, to prevent RF from being radiated by a steel case or copper or whatever? I know it is a safety issue also, if not grounded, high voltages can appear but what about radiation? Does grounding help lower RF being radiated by the case of the vacuum system?