I would be very cautious about putting an electrical device in a fuel cell.
  One person has already blown up a Lancair wing and blown himself up in the
  process, too. And that was just from sanding on the outside of the wing.

Jeff,

 

You Bet!  I use a special polymer compound for exceedingly slick wings to achieve unbelievable race speeds.  The second step for a successful application is just a light wipe down with a terry cloth towel.  In the winter, in my heated but non humidified hangar, I can barely hear Rush on the AM radio because of the static generated as I towel down the finish.  Hopefully, the lightning bolts are only betwixt the wing surface, the towel and me.  I cannot bear the thought of ending up splattered all over my hangar - my recurring dream is that my end will come as the result of a backing garbage truck at OSH and the last thing I will hear is that annoying beep-beep-beep.

 

It's probably OK to electrically inspect the interior of a wing that has never been introduced to fuel.  Ignitable fumes could be emanating from obscure corners in the many compartments of an "empty" wet wing - especially in a Legacy.

 

Have a blast,