I have a 97 Deville. Intermittently, the Brake Light illuminates, immediately followed by a dashboard message stating "Service Brake Fluid Switch." The message then disappears after a few moments. It is not accompanied by any loss of braking.

I've checked:
All brake lights (and other lights), and they are functioning.
Brake fluid reservoir is filled
ABS and traction control appear to be functioning properly.

Does anyone have any ideas on what the issue is? I've seen other posts on other forums with similar issues, but no resolution.