"bell-ringer, one employed to ring church or processional bells," early 15c. (c. 1200 as a surname), agent noun from ring (v.1). An early 13c. text has belle ringestre "nun who rings the convent bell."
In quoits (and by extension, horseshoes), "a throw cast so as to encircle the pin," from 1863, from ring (v.2).
Expression be a dead ringer for "resemble closely" (1891) preserves ringer in the horse-racing slang sense of "a fast horse entered fraudulently in a race in place of a slow one." The verb to ring in reference to this is attested from 1812, possibly from British ring in "substitute, exchange," via ring the changes, "substitute counterfeit money for good," a pun on ring the changes in the sense of "play the regular series of variations in a peal of bells" (1610s). The meaning "an expert" is recorded from 1918, Australian slang, from earlier meaning "man who shears the most sheep per day" (1871).