Postgresql insert has more expressions than target [duplicate]

I know this has been asked and answered but I'm still unable to get this trigger function to insert correctly. I know I have the same number of values being inserted but keep getting the has more expressions than target. The only difference in columns structure, is that namespace2.t1 has one extra column that is not included in namespace1.t1; which is why I can't just SELECT * from namespace2.t1

CREATE 
OR REPLACE FUNCTION upsert_trigger_function() RETURNS TRIGGER AS $$ 
BEGIN
  INSERT INTO
    namespace1.t1 (col1, col2, col3, col4, col5, col6, col7, col8, col9, col10, col11) 
    SELECT
(col1, col2, col3, col4, col5, col6, col7, col8, col9, col10, col11) 
    FROM
      namespace2.t1 
      ON CONFLICT (col1) DO 
      UPDATE
      SET
        col2 = namespace2.t1.col2,
        ... 
      WHERE
        namespace2.t1.col1 = col1;
RETURN NEW;
END;
LANGUAGE 'plpgsql';

And my trigger:

CREATE TRIGGER upsert_namespace1_t1 after INSERT 
OR 
UPDATE
  ON namespace2.t2 FOR EACH ROW EXECUTE PROCEDURE upsert_trigger_function();