If you've ever touched a live wire in a home electrical circuit, such as in a wall socket or switch, that's the extent of a shock you can get from a pin. I suppose there are situations where it can be deadly, like if you're standing in water, but in the main, you're just going to get bit a bit. Only rarely deadly. That said, don't go searching it out either. Other than that, the most you're going to get on most circuits of any pin is 50v. As noted above, anything carrying line voltage with have plastic insulation on it.