Seems like having a predilection for something that kills you is not an instinct that should be selected for. If they are electrocuted by the electronics shouldn't this problem take care of itself sooner or later?
I suspect that it depends on whether sensitivity to electrical fields is useful in other contexts, or(if not directly useful) at least tightly-coupled to some other sensory mechanism that is survival-critical and will take quite some time to iterate toward an electrically insensitive replacement.
Mass death upon the power lines is obvious folly; but electrification is, what, a century old(in any ecologically-relevant amount, I know about various independent developers of primitive chemical batteries going back a great deal further; but that sort of scale barely matters), the blink of an eye in evolutionary time.
If this electrical sense isn't all that useful elsewhere, or is just some accident that didn't previously cause trouble, it could actually be culled from much of the population fairly quickly. If it has some other use, or is connected to genes that code for multiple things, some of them extremely useful, they might take ages, if ever, to stop doing this.