A fetish is an object designed to house a spirit being. Traditionally, a fetish is the physical representation of an honored spirit, for example, an ancestor, deity or spirit guide, thus creating a physical and often (but not always) portable object for the bearer to interact with as they would the spirit-being they wish to honor, presenting it offerings, praying to it, with the understanding that the interaction is not with an inanimate object, but with the spirit that resides inside. In turn, the possessor of the fetish might receive blessings of luck, protection, etc. and perhaps more active magical abilities as well.
Fetishes may also be used to house other types of spirit beings including servitors whose purpose is to aid the possessor of the fetish in some way or to bring mischief or a curse upon someone nearby, or the immediate location.