I just got an email from Amazon all in Spanish saying I am being charged $232 for the mexico marketplace and one from Amazon.ca charging me $15 for Canada marketplace. Stating it’s to settle an account balance. I have not sold in either marketplace. 
This is also the first time I’ve received something like this.
You should contact Amazon’s customer support to inquire about these charges and clarify the situation. Did you notice any unusual activity on your Amazon account recently?
Hi, it seems like my products are active in these markets but I never listed them and I don’t know why I am attracting the charges. I am selling in the US.
Disable your products listing in other markets and only select the relevant marketplace. This help you to stop extra charges for other market places.
That would be a red flag.
Do not click on any links in the message and it is best if you disable remote content from loading.
If it does not show up in your official seller central messages I would reach out to amazon to verify that it is a legitimate message from them. Make sure that you are incontact with the actual amazon company.
It sounds like Amazon automatically translated and listed your products across international marketplaces. In order to stop selling internationally, firstly disable all international shipping options in your main Amazon USA marketplace’s Shipping Settings:
https://sellercentral.amazon.com/sbr/ref=xx_shipset_dnav_xx#shipping_templates
Then also remove the connection with other North American marketplaces after following this link:
https://sellercentral.amazon.com/global-selling/listings/connect?ref_=xx_BIL_snav_agsLand
And once the connection is removed, delete any inventory on the additional Amazon sites and place the accounts on Vacation settings:
https://sellercentral.amazon.com/hz/account-info/vacation-settings?ref_=macs_gvacatn_cont_acinfohm