I recently received a consent of guardianship form stating that my ex-wife is seeking guardianship for my 18 year old son. He lives in a home for disabled children.
The consent form does not show that it has been filed through the court system. My question is: "Is this the proper way of seeking guardianship or should I question this further?" Please advice

Definitely question it further. Contact an attorney and present him/her with a copy of the form in question. If you don't know an attorney then contact the Lawyer Referral Service for your county of residence and inform them that you need to consult with a family lawyer concerning guardianship of a disabled adult child.

Is this child a regional center client... because even if she is granted guardianship, regional center will keep an extra close eye on him and his rights as an adult. They are very active with "personal rights". Does he live with you and she wants him to live with her? If so, I would try to make sure that you are his "payee" with all his finances. Regional center can assist with that. Any other questions you have regarding your son, I am sure regional center can assist you with... they are a great support and service.