Avodas Kochavim 5:2
One who proselytizes to an individual is called a meisis; if a person proselytizes to the majority of a city’s residents, he is called a madiach. If a madiach is a prophet, he is punished by stoning and those who were led astray are judged as individuals, not as residents of a condemned city. The laws of a condemned city only apply when two people lead the inhabitants astray.
If someone says, “This idol told me to serve it,” or “God told me to serve an idol,” he is considered a prophet leading others astray. If the majority of a city is swayed by his words, he is punished by stoning.
A meisis is stoned to death whether he proselytized in the singular – for example, “I will worship an idol,” “I will slaughter,” “I will offer libations,” “I will bow down,” etc. – or in the plural – “Let us worship,” “Let us slaughter,” “Let us offer libations,” “Let us bow down,” etc. When a meisis tries to proselytize two people, they may testify against him as witnesses. They summon him to court and relate what he said to them, after which the meisis is stoned.
Avodas Kochavim 5:3
A meisis does not require a warning. If he proselytizes to a single individual, the target should tell him, “I have friends who would be interested in this.” By doing so, the meisis will come to proselytize in front of two people, which is necessary for him to be executed. If he refuses to proselytize in front of two people, there is a mitzvah to entrap him. There is no mitzvah to entrap a person who violates any other Torah law; this is the only such case.
The trap is set as follows: The target brings two people and hides them in a dark place where they can see and hear the meisis but he cannot see them. The target tells the meisis, “Repeat what you told me before.” When he does so, the target should respond, “How can we turn our backs on God in order to serve wood and stone? If the meisis retracts his statement or remains silent, he is not liable for execution. If he responds by telling the target that we are obligated to serve the idol and that it is to our benefit to do so, then the hidden witnesses have him summoned to court, where he will be stoned.