The home set used is actually a somewhat redecorated, but still recognizable version of The Brady Bunch (1969) living room & staircase. The Brady Bunch had already ended a full year before on ABC in 1974. Both shows were produced at Paramount, the Brady home set was used several times during the 8 season run.
Last show of the series.
The living room and fireplace, including the iconic staircase to the upstairs bedroom area, of the "Brady Brunch" TV show was shown in one scene.