A recent exhibition at Kaohsiung Museum of History featured dozens of folk-religion effigies and images.
For me, the most interesting artifact was an icon of a Catholic priest (pictured right) from a mountainous part of rural Kaohsiung. Unfortunately, the label does not reveal if the aborigines who carved the statuette prayed or made offerings to it. (If they did, did they regard the priest as an addition to their pre-exisiting pantheon, or were they converts to Christianity who treated him as a saint?). Nor does it say when the carving was made.
Also intriguing is this effigy of Liao Tian-ding (廖添丁). Like many other divine personalities, Liao (pictured lower right) was once an ordinary human. However, unlike most of the entities worshipped in Taiwan's folk temples, he was born and died in Taiwan. Revered for fighting the Japanese then in control of the island, icons of him began appearing in temples soon after his violent death in 1909. Some biographical details can be found here.