If the bank told me my wife had a secret account, legally how do I find her other accounts?

File your petition for dissolution of marriage with the court and have a process server serve it on your wife.  She has to respond by filing an answer within the time set forth in the summons (the time for a response varies from state to state).  After her answer has been filed, then you serve her by mail with a request for production of documents.  Your request for production of documents  should include all of her accounts, the account number for each account and the name and address of the bank or other financial institution and/or place where the account is located.  You can file an amendment to your petition for dissolution of marriage when you obtain this financial information to include this new information.

Your Request for Production of Documents is not filed with the court.  You just serve it by mail on your wife.  Serve by mail means you send it with a proof of service.  The proof of service verifies the date of mailing.  You can either use a court form proof of service or you can write your own.  If you write your own, it just says that you are over eighteen and the attached documents were sent via first class mail unless stated otherwise to __________ (name and address of your wife) on __________ (date).  You sign and date at the bottom.  The date you sign should be the same as the date of mailing.

The Request for Production of Documents would have the name of the case, case number and name and address of the court.  It would just say Petitioner requests that Respondent produce the following documents:  (list the items I mentioned above regarding the bank accounts) and set a deadline for a response.  You sign and date at the bottom.

As for your question about splitting assets, yes, assets are divided upon divorce.  If you live in a community property state, community property is property acquired during marriage.  Community property also includes income during marriage.  Each spouse has a one half interest in the community property.  Spouses can agree to an unequal division of community property.

Separate property is property acquired before marriage or after the marriage ends.  Separate property also includes income before marriage or after the marriage ends.  A spouse has no claim to the other spouse's separate property.