By Christian D. Barnard
Divorce Lawyer, Cordell & Cordell
If your ex-wife's new boyfriend is verbally or physically abusing your child and you are concerned for your child's mental and physical safety and wellbeing, most jurisdictions have a process through which you can ask the court to award you emergency custody.
Typically, this process requires that you file a document with the court alleging that your child is in danger describing the situation and your concerns. The court will likely hear your allegations very quickly.
Most states have rules that require a court to hear such cases within a day or two of filing when there is an emergency.