Dear Eli,
Good day. Thank you for posting to Microsoft Community.
Based on your description, you want to get the electrical stencils for Visio. May I know are you referring to the engineering drawing shown below?

If yes, you can refer this official article to create the electrical engineering diagram. Reference for you: Create an electrical engineering diagram - Microsoft Support. If you can't find the template in your Visio application, download it via this article: Featured Visio templates and diagrams - Microsoft Support
If above can’t satisfy your needs or you mean other stencils, I’m afraid there is no related stencil could meet your requirement. I recommend that you contact the administrator and let him open the support ticket with a Support Team that has higher permission to further assistance: Get support - Microsoft 365 admin | Microsoft Learn
Thank you for your understanding and time. And your patience and cooperation will be greatly appreciated.
Sincerely,
Claire | Microsoft Community Moderator