Building a custom line splitter

List of materials listed below. How to build your own custom line splitter to take power factor, volts, watts and amperage reading all at the same time. Display https://www.amazon.com/gp/product/B07... Plastic Box https://www.amazon.com/gp/product/B08... Power Cord https://www.amazon.com/gp/product/B00... Connectors https://www.amazon.com/gp/product/B07... Cord Strain Relief Connectors https://www.amazon.com/Arlington-LPCG...