Update April 13, 2019: I posted new wiring diagrams for 4-Way electrical switches today.  The diagrams depict two methods of installing wiring for 4-Way switches.  4-Ways are called intermediate switches in some countries.  I have also updated my post explaining 3-Way switches which are 2-Way in some countries.  I welcome any suggestions you may have as well as complaints.  Please be safe when working around your home, especially with electrical wiring and electricity.  Thank you for visiting.