On the employment website, www.indeed.com, there is a listing for a psych home health RN for Amedisys in Lake Forest CA. The zip listed is 92630 so it is the southern CA Lake Forest and not the Lake Forest that is near Sacramento. There may be other job listings. However, must warn you that several people have posted that Amedisys is not the best company to work for, so investigate fully before you take a job with them.
You should be in hot demand just about anywhere. There are requirements over and above that of a home health RN for seeing psychiatric patients. My best advice is to ask around about agencies first. You want to work for one with a reputation for high quality. You can look up some information at www.medicare.gov under the home health compare option. Also, if you are a psych RN, maybe you can check with some of the psychiatrists you know to see if there is an agency they prefer.
You should have no trouble locating an agency that will hire you.
The home health agency submits your resume and qualifications to the intermediary (contracted payer for Medicare in your region) and they determine whether you meet Medicare's guidelines. The agency itself must be approved to provide psychiatric home health services. This usually requires at least two Medicare approved psychiatric nurses on their staff. Nurses that qualify are greatly in demand.