The Metlar House, also known as the Knapp House, the Bodine House, or the Metlar–Bodine House, is an historic house, now museum, located along River Road in Piscataway, New Jersey. It is also believed to be haunted. In 2003 a fire badly damaged the house. The museum has undergone major renovations over the past decade and, as of Summer 2014, is once again open to the public.

The Metlar–Bodine House's "Red, White, and Boom" Madeira wine tasting event on July 6, 2014, kicked off its campaign to raise money to build a new educational wing to house the historically significant Ross Hall Wall.

In July 1778, George Washington headquarters were at Ross Hall and his 11,000 patriots camped along the Raritan River in Piscataway. It was there that General Washington wrote the first order for the United States Army to celebrate the 4th of July – a tradition that continues to this day. The troops were ordered to march across the river on Landing Lane Bridge, line the banks of the Raritan in New Brunswick, and shoot their rifles down and up the line in the first organized salute to the nation's independence. They were then given an extra ration of rum and that evening the General had a party for officers (including Alexander Hamilton, the Marquis de Lafayette and Baron Von Stuben) and their ladies at Ross Hall. The building was destroyed in the 1960s but because of its significance, a parlor wall was saved and was exhibited at the New Jersey Historical Society until it was given to the Township and the Metlar–Bodine House in 2000.

Currently, the parlor wall is dismantled and stored in a large warehouse owned by Piscataway Township. The wall must be restored and relocated to a facility that is climate controlled and protected. It is estimated that the wall's restoration and an addition to the Metlar–Bodine House will cost close to $1 million.