It amazes me how often strange anomolies slip through safety procedures. I use a voltmeter to check before working on wiring, and like you, have still managed

It amazes me how often strange anomolies slip through safety procedures. I use a voltmeter to check before working on wiring, and like you, have still managed to grab a live wire more than once. Last time, it was a situation much as yours - had the breaker off for the circuit I was certain I was working. And I checked with the voltmeter. But like a damned fool, I only checked the hot to ground voltage, and not the neutral to ground, or hot to neutral. Yep, you guessed it - the outlet was on a circuit for a different room, and was miswired in a junction box, reversing neutral and hot. I got the full benefit of the 120v. Fortunately, standing on a dry wooden floor in rubber soled shoes, I was a lousy path to ground, but still a dangerous situation I have no desire to repeat.