Accidentally Touching One Lead Of A Multimeter While Other Is In Electrical Outlet
If the multimeter is set to read voltage, it will have a very high-resistance, so if everything is working correctly touching the other lead will not shock you.

If it's set to read current, it will have almost 0-resistance, so touching the other lead would be equivalent to touching the bare wire.  Thus, having the multimeter plugged into the hot-slot and touching the other lead will shock you (but, having it plugged into the neutral won't)