2001 Ford Windstar Dash lights with both brake and ABS

Electrical problem
2001 Ford Windstar 6 cyl Front Wheel Drive Automatic

For 3 or more years on occasion both the red brake light and the orange ABS lights will light at the same time. When the key is turned to the off position, it resets the lights to stay off for a while before reappearing. It causes no problem with brakes or operation and it might go for weeks without coming on. At other times it may come on every time you drive it for a week or two and then just fade away for a while before reappearing again later. It seems like a loose connection or a loose ground that heels itself. I added extra ground cables, but did not help. Have you ever heard of anything like this and is it something you can tell me how to fix?