We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember saying something
like:

So, the moral of the story is, make sure you know what's in there, "before"
you start drilling any holes.

With a lot of houses there's no way to know. A more sensible approach
would be safer drilling practices, ie not touching any metal part of
the drill while drilling.

Or being bloody cautious if drilling within 6" of the door frame, where
many switch cables are anyway.