Wrapping things in metal more often than not produces worst emissions than a bare circuit board. This is because you set up a resonant cavity inside producing a much stronger field. Then it gets onto the wires going into / out of the metal box and radiates that way.
As well as radiated emissions there are conducted emissions through cables, as well as susceptibility tests to perform. In addition depending on the class of device you might have to pass surge tests where large voltage spikes are put on the line. Then there is the ESD tests where you zap everything accessible to a user with 2 to 4 KV of electro static discharge.