Remove Special Character

 REGEXP_REPLACE(AC.CUSTOMER_NAME,'[^'||CHR(1)||'-'||CHR(127)||']','')

For Example:

SELECT REGEXP_REPLACE(AC.CUSTOMER_NAME,'[^'||CHR(1)||'-'||CHR(127)||']','') AS CUSTOMER_NAME   FROM AR_CUSTOMERS  AC  WHERE AC.CUSTOMER_ID = 253889