What happens if you break a rule of a mosque?

Answer 1

This is an unusual question!

The answer depends on the rule that is broken and why it is broken.

If a person breaks a minor rule, like wearing shoes on the carpet where people pray, others will remind him/her to remove the shoes.

If a person creates a disturbance, s/he may be reminded to be quiet. If the disturbance continues, s/he may be asked to leave.

Answer 2

For different rules of Hajj different penalities have been describes. Generally slaughtering a goat or keeping fast for ten days is prescribed.