In general, you don't need an attorney to pay off your mortgage. However, before paying it off, you should contact the mortgage company to detetermine its procedures for relinquishing the lien on the property.
You may contact the servicer or noteholder and ask for a payoff amount. Once the mortgage is paid off you may loose certain rights against the current noteholder if any irregularities existed in the origination or servicing of the loan, such as misapplication of fees and expenses.