What is the ruling on a husband wearing a silver wedding ring if he fears his wife's anger, and is that considered shirk (polytheism), and what is its expiation, and is bid'ah (innovation in religion) considered a departure from the fold of Islam?

Wearing a wedding ring is a tradition alien to Muslims, and it is not permissible if the intention behind it is to imitate disbelievers. If it is free from the intention of imitation and the belief in its تأثير (effect), then it is not haram, but refraining from it is more preferable. It is not permissible for a Muslim to do anything that involves a violation of Islamic law to please anyone, based on the Prophet's (peace be upon him) saying: "There is no obedience to a creature in disobedience to Allah Almighty." This act is not considered shirk (polytheism).