I just completed my Jury duty. I was very lucky not to be chosen as a grand jurar, as that would mean an automatic two weeks of duty. From what I understood, there isn't even a chanceof being dissmised in the process of voir dire in a Grand Jury, as we don't actually sentence anyone, rather just decide if a case should go to trial or be dismissed (perhaps AJK or someone else with law knowledge can confirm if that is true).
@ Reb Jo, if you're not living at that address, much more so if you're living out of state, I think you can ignore the summons.