fetish

Something which is believed to possess, contain, or cause spiritual or magical powers; an amulet or a talisman.

The idols and fetishes were being dressed up and whitewashed, receiving sacrifices.

A figure representing the spirit of a deity, human, or animal; an idol or voodoo doll.

This was the trunk of a large wooden doll […] now entirely defaced by a long career of vicarious suffering. […] The last nail had been driven in with a fiercer stroke than usual, for the Fetish on that occasion represented aunt Glegg

Sexual fixation to or arousal at something abnormally sexual or nonsexual, such as an object or a nonsexual part of the body.

I know a guy who has a foot fetish.

a fetish for leather

An irrational or abnormal preoccupation or fixation on some object or activity; an obsession.

He has been talking about the same topic for hours on end, I suspect he may have a fetish

However, I am not prone to sensitiveness, and the following of a sense of duty, wherever it may lead, has always been a kind of fetich with me throughout my life; which may account for the honors bestowed upon me by three republics and the decorations and friendships of an old and powerful emperor and several lesser kings, in whose service my sword has been red many a time.

A recurrent theme of a specific thing.