You Need One Of These

http://www.romancatholicman.com/st-benedict-medal-with-exorcism-blessing/

There is indeed no medal that possesses such wonderful power and none so highly esteemed by the holy Church as the Medal of St. Benedict.

Whosoever wears this medal with devotion, trusting to the life-giving power of the holy Cross and the merits of the holy Father St. Benedict, may expect the powerful protection of this great Patriarch in his spiritual and temporal needs. The medal is one of the oldest and most honored medals used by Catholics and due to the belief in its power against evil is also known as the “devil-chasing medal.”

As early as the 11th century, it may have initially had the form of Saint Benedict’s cross, and was used by pope Leo IX. The reverse side of the medal carries the Vade retro satana (“Step back, Satan”) formula, which has been used by Catholics to ward off evil since the 15th century.

Sometimes carried as part of the rosary, it is also found individually. In widespread use after its formal approval by Pope Benedict XIV in the 18th century, the medal is used by Catholics to ward off spiritual and physical dangers, especially those related to evil, poison, and temptation.