During the time that the two Shapiro brothers of Slovita were imprisoned they were cast into a jail cell with many other prisoners. Due to the dirty, filthy state of the cell, they were halachically forbidden to daven. One of them said to the other: Let us sing a niggun! The niggun they sang roused the spirits of all the inmates and before long they all broke out in a dance. When the warden and guards saw this they ordered the Shapiro brothers separated from the other prisoners and as soon as they were in their own cell they breathed a sigh of relief! Here, they would now be able to serve Hashem properly. One brother said to the other: I now understand the meaning of a kameo amulet that the Baal Shem Tov once gave to a wealthy man that invited him as his guest.
The Baal Shem stayed with him, and all Shabbos he did not utter a word. on Motzaei Shabbos the wealthy man's wife requested that the Baal Shem daven that they achieve salvation and have children. The Baal Shem Tov made havdalah and called the wealthy man to look into the cup, where he saw in the reflection an evil harmful spirit seeking to harm and injure him! On the spirit were written letters Yud Shin Bais, Shin Bais. Until now I had no idea what this meant. However, now I think that perhaps it stood for the acronym Yehi Shalom BeCheilach Shalva BeArmonosayich (Tehillim 122:7). (Sippurei Maran HaRamach Baal Shem #15, Shemous veSippurim Volume I pg 244 as cited by Likkutei Imrei Pinchos Sha'ar Sippurim 122)
