the runner on third would be in jeopardy of getting thrown out. he/she can steal home even on a walk. the only way he could not be called out is if the walk forces him home. a runner on second can attempt to steal third when the batter is walked and no one is on first. if no one is on first and second and the runner on third attempts a squeeze play and the batter is walked he can be thrown out. for him it is a live ball.