Red led is the fault light ( or amber if neon)
When the switch (fuse) is closed you will not see the red light till a faulty fuse ( open switch = bad fuse)
If your A.C. fuse blows this will show you.
On mains use a neon for this application.
Please don't try this unless you are qualified to work with mains power. Get help if you need this circuit, stay alive don't take chances.
