This website says it does normal damage, but I'm pretty sure it doesn't.
Ah yes it does, but only in generations before six. In the new X and Y games coming out this Saturday Steel types will no longer resist Dark or Ghost type moves; however they will gain a resistance to Fairy types, the new type introduced in Kalos.
As of X and Y, they have changed the resistances of steel, along with the new fairy type. Im pretty sure that steel lost its resistance to ghost when that had happened.
Source: Watching a bunch of X and Y videos on youtube.
