I am a fifth grade student, and I recently uncovered a P & S wiring cleat from around the 1900's. I am looking for as much historical information as I can get. If you have any other history about when homes started to use wiring cleats or any history about electric wiring would be really helpful. Thank you, Madison Schenker 1. During what years did P & S manufacture these cleats 2. How common is it to come across these now? 3. When did electricians stop using this type of insulator, and what technology replaced it? 4. Why was it called the "P & S No. 3"? 5. Who invented them?