2002 NEC:Article 314.25(B) Exposed Combustible Wall or Ceiling Finish. Where a luminare(fixture) canopy or pan is used, any combustible wall or ceiling finish exposed between the edge of the the canopy or pan and the outlet box shall be covered with a non combustible material.(IE: Wood Siding) I only know of Arlington Mfg that sells these "Spark Guards" and have discovered that the ones for the round boxes (BE1R) are to big to fit the Bowers or Carlon(3R16NGP)most widley used boxes; When I asked the Mfg I was informed to "Slit The Corners" then what is the point in having the "Spark Gards" in the first place if you have to alter it; Does anyone have any suggestions of a better way?