Subject: How might someone survive electrocution after a radio falls in his bathtub?

I am researching a script for the television series "Mysterious Ways."  In the 
story for this episode, a person is taking a bath when a working radio falls 
into the tub.  The person convulses, reacting to the electrical current in the 
water, but miraculously, survives.  So my question is: how might that be 
possible?  Is there some reasonable explanation?  What might have 
prevented/interfered with total electrocution?  Perhaps something to do with 
the kind of material the tub is made from?  Or something in the bathwater?  The 
soap the person had covering his body at the time?  Any ideas, no matter how 
farfetched, would be much appreciated.   

Re: How might someone survive electrocution after a radio falls in his bathtub?