Did you set a Kerf value in Swill's program??
You have to set a kerf value on all laser-cut items to account for the thickness of the laser when cutting materials. If you don't set a value, all your holes will be too big, because of the extra material removed from each side of the cut line.
Kerf will vary a bit from one manufacturer to the other. I usually set the kerf to 0.15mm (which will work for most lasercutters), and my switch plates have come out perfectly, and switches fit very snug.