Q: Why does my wife sometimes receive texts I sent to other people? We share an Apple ID, but it doesn't always happen.

Hello there, HARKlyce.

I'm sorry to hear about the misunderstanding of your message by your wife. It sounds like both of you may be receiving messages because of the shared Apple ID. The Apple ID FAQ reviews some great information and touches base on shared Apple ID:

Frequently asked questions about Apple ID - Apple Support

Can I share my Apple ID with someone else? 

You shouldn't share your Apple ID with anyone else. It provides access to personal information including contacts, photos, device backups, and more. Sharing your Apple ID with someone else means you're giving them access to all your personal content, and it may lead to confusion about who actually owns the account. 

To share photos, a calendar, iTunes purchases and more with someone else, try these sharing features. 

Alternatively, you can select what phone number and or Apple ID is used for messages by going to "Settings > Messages > Send & Receive > You can be reached by iMessage at:"

iOS and OS X: Link your phone number and Apple ID for use with FaceTime and iMessage - Apple Support

Thanks for reaching out to Apple Support Communities.

Kind Regards.