Is there a tool for removing the outer sheathing on cables such as Romax?

A utility knife will work, but an inexpensive cable ripper is designed for the task and will not damage the wires inside.

Check your state and local codes before starting any project. Follow all safety precautions. Information in this document has been furnished by the North American Retail Hardware Association (NRHA) and associated contributors. Every effort has been made to ensure accuracy and safety. Neither NRHA, any contributor nor the retailer can be held responsible for damages or injuries resulting from the use of the information in this document.