Does the divorce occur by saying, "By divorce, you will not sleep at your family's house on Wednesday," if the wife sleeps at her family's house on Wednesday?

Divorce by writing takes effect if the husband intends it. So, if the wife stays at her family's home with the husband's intention of divorce based on what he said, then it is valid; otherwise, it is not. In the event of divorce, the husband can reconcile with his wife before the 'iddah (waiting period) ends, provided this divorce does not complete the three (divorces).