Converted from c=λf: λ = cf = 3×108m/s9.0/kloc-0 /×107hz = 3.33m,

(2) According to the principle of safe use of electricity, a grounding conductor should be installed between the plug and the socket, but the components are not.

So the answer is: (1) 3.33; (2) There is no grounding wire installed between the plug and the socket.