Brewer police, with help from the Bangor Bomb Squad, dismantled an old grenade that turned up inside a box at an accounting firm in Brewer on Tuesday. Police went to Beathan, Bernier, Seekins and Colpritt CPA on Parkway South at about 10:30 a.m. after an employee discovered the device inside a box of papers. The boxes belonged to a deceased client whose family members brought them to the accounting firm for review, Brewer Sgt. Arden Jones said Tuesday afternoon. There was nothing intentional or suspicious about the bizarre find, he said. Police cleared the office building and shut down the firm’s parking lot and part of the parking area for the post office next door for about two hours. Jones said the grenade was a World War II-era device that did not appear active, but it was destroyed anyway as a precaution, the sergeant said.