Steam and Electricity If an electrical  conduit with sufficient voltage were cut and lay naked inside a chamber of steam, would an electrical arc occur?  As a secondary question, if the steam were subject to a stabilized pressure wave, in what manner, if any, would an arc occur?
 A: I see you edited the question from a sauna to what I assume is a insulated test chamber.  Steam would have very little change in the voltage required to getting a spark.  You would also need more than just a bare wire, you would need a grounding plate inside your chamber.  The voltage would primarily be a function of the air gap separating your wire and your ground.  Any ionized gases would assist in lowering that voltage threshold, whereas water vapor would probably not change the conductivity much at all.
For your second question, steam in an acoustic standing wave probably wouldn't have a noticeable effect.  You really need a gas that can conduct.  In plasma physics this is called an ion pressure wave.  These waves are used to excite and conduct the plasma usually between two electric plates like your wire and ground.
From the comments I think you want the current to flow along the direction of the wave like a wire, but it actually would flow perpendicular to it.  This is where the gas gets compressed increasing the amount of free electrons available for conduction.
