Carpet as a Base and fears of fire

I've seen layouts where people use a short-pile carpet, I think it's called "Berber," as a base for their trackage on the layout table.  The thing is, they don't run the wiring under  the carpet, they drill the table and run the wiring under the table and up through  the carpet.  That way the wiring's always accessable and doesn't lead to other issues.