Under what circumstance is an object considered Mukse in one area, but entirely permissible for handling in other locations?
Such a situation, interestingly enough, arises when Purim – the fourteenth of Adar – occurs on Friday.
Generally speaking, it is entirely permissible to handle a Megila on Shabbat, just as Halacha permits handling Torah scrolls, Haftara scrolls and ordinary books on Shabbat. Since these articles are used for reading and studying, Halacha permits handling and using them on Shabbat.
The one exception to this rule is when the fifteenth of Adar falls on Shabbat. Normally, Jews in Jerusalem observe Purim on this date – the fifteenth of Adar (as opposed to other locales, where Purim is celebrated on the fourteenth). When the fifteenth falls on Shabbat, however, the Sages forbade reading the Megila, out of concern that somebody might mistakenly carry the Megila through a public domain, in violation of Shabbat. The Peri Hadash (commentary to the Shulhan Aruch by Rav Hizkiya Da Silva, 1659-1698) ruled that once the Sages forbade reading the Megila on Shabbat in such a case, the Megila becomes Mukse. Thus, in this particular instance, when the fifteenth of Adar falls on Shabbat, it is forbidden for the Jews in Jerusalem to handle the Megila. Elsewhere, however, one may handle the Megila, since they do not observe Purim on that day and there is thus no Rabbinic enactment forbidding Megila reading.
Summary: It is permissible to read, study from or move a Megilat Ester scroll on Shabbat, except when the fifteenth of Adar falls on Shabbat, in which case people in Jerusalem may not handle a Megila on this day.