I have a switch on the wall that doesn't seem to do anything. I decided to investigate by pulling the switch out and to my surprise, it was a 3-way switch with only two connections (black and white but no red wire). An even bigger surprise was that the white wire always measured live on my outlet tester regardless of the position of the switch. I figured that either the switch had failed short or the white wire was connected to live for some reason. I disconnected the switch and the white wire still tested live. I did a continuity check between the black and white wire (with the breaker off) and found that there was indeed a direct connection.
All of this explains why the switch didn't do anything. What I can't explain is why this junction box was wired like this in the first place. I've changed just about every other switch/outlet/light fixture in the house and this is the only instance I've seen of dubious electrical wiring. I'm chalking it up to an electrician's error and planning on capping the two live wires and putting an unconnected dummy switch into the wall. Does anybody have a better idea on what might be going on here or what I should do about it?