Firefighters were called to the old Mill Lane WMC on Mill Lane in South Kirkby, near Pontefract, just before 3pm today.
A spokesman for West Yorkshire Fire and Rescue Service said the derelict single-storey building was “well alight”.
Crews from South Kirkby, Pontefract, Normanton and Wakefield remain on the scene.
The building was also hit by a fire late last month.
A planning application has been submitted for the demolition of the site and the construction of 14 homes in its place.