CREATE TABLE table_name_38 (date__to_ VARCHAR(255), traction_type VARCHAR(255), name_of_system VARCHAR(255))
What is the date (to) associated wiht a traction type of electric and the Yarmouth Light and Power Company system?
    
SQL: SELECT date__to_ FROM table_name_38 WHERE traction_type = "electric" AND name_of_system = "yarmouth light and power company"