I have written poems and articles about bells previously on this blog, but I haven't covered the symbolism of bells.  
    Bells symbolize consecration, purification, or a charm against the powers of darkness.  They can also symbolize heaven and the voice of God.  The bell swinging back and forth represents the extremes in the world of duality: good and evil, death and immortality, material and spiritual.  A ringing bell can be a summons or a warning.  Bells are rung in many churches and temples for various reasons.  Large bells are rung to call people to services.  Small bell rang during services are announcing the presence of Christ.  In Buddhism, a bell represents the pure sound of the doctrine of wisdom.  
    In Tibet, a ceremonial bell called a ghanta is used in Buddhist rituals and represents femininity, wisdom, receptiveness and the voice of Buddha.  It is always used together with the dorje, a male symbol.
    "Bell, Book and Candle" is the name of an old movie about witchcraft, so most people are likely to associate it with witches but, in the Roman Catholic Church, a solemn form of excommunication is: "to curse by Bell, Book and Candle". 
    In old Europe, nearly every town had a bell tower of some sort.  The bell was rung to announce births, deaths and weddings.  The famous Leaning Tower of Pisa is a bell tower.