Invalid character found in a character string argument of the function "DECFLOAT"

Question

This is my query:

SELECT  GROUP_ACCT.GROUP_ACCT_ID,GROUP_ACCT.GROUP_ACCT_NAME,
        REMINDER.PAYMENT_REMINDER_TYPE,REMINDER.SEND_DATE

FROM CWS.TPR_M_GROUP_ACCT GROUP_ACCT 
   LEFT OUTER JOIN CWS.TPR_TTRN_REMINDER REMINDER
           ON REMINDER.GROUP_ACCOUNT_ID=GROUP_ACCT.GROUP_ACCT_ID 
WHERE GROUP_ACCT.GROUP_ACCT_NAME LIKE ?";

And from the prepared database I am setting value of bind variable (?) whose value is for example %T%

But I am getting this error and the datatype of the column of GROUP_ACCT_NAME is varchar2.

Initially it was working but I am not able to understand from where function "DECFLOAT" came into picture