You need to contact a local lawyer... but generally an owner is free to put up cameras in his house. What he does with the video may be another story. But every state has different privacy laws so it is hard for me to say with certainty. If this is the activity going on, you may want to contact a family lawyer.
I am sorry that you are going through this. The home is as much yours as it is his, the cameras are "creepy" and the court will not like this, find a lawyer and use his or her PI to take pictures of the cameras and then bring a motion to the court to have them removed, if he won't remove them, you should consider filing a civil/ criminal action if appropriate. take care and hope that things work out.
Legal disclaimer: The response given is not intended to create, nor does it create an ongoing duty to respond to questions. The response does not form an attorney-client relationship, nor is it intended to be anything other than the educated opinion of the author. It should not be relied upon as legal advice. The response given is based upon the limited facts provided by the person asking the question. To the extent additional or different facts exist, the response might possibly change. Attorney is licensed to practice law only in the State of Massachusetts. Responses are based solely on Massachusetts law unless stated otherwise.
California is a community property state. It's quite likely [though not for certain] that both the house and the cameras are community property -- which means that you, as half of the community, are an owner of the house and the cameras. Speak with your own family law attorney but I see no reason why you simply can't remove the cameras yourself.
The above is general information ONLY and is not legal advice, does not form an attorney-client relationship, and should NOT be relied upon to take or refrain from taking any action. I am not your attorney. You should seek the advice of competent counsel before taking any action related to your inquiry.