My child's father is living with someone I suspect to be dealing ilegal substances. The father has visistation every other weekend. I do not want my child to be in that home. I have custody. What are my options?

If there is a court ordered visitation schedule then you would have to go back to court to ask for supervised visitation. You will need to do more than "suspect" illegal activity.

If there is no court ordered visitation, then you can insist that he visit in public places. This will force him to go to court for visitation and you can then bring up your suspicions. But without proof, the court may grant unsupervised visits.