95 E320 brake pressed engine revs

[benmack1]

My wife's 95 E320 wagon has been giving her some problems. She tells me when she pushed the brake today, the engine started to rev (all the way up to 3K). She claims her foot was not on the gas and has been mentioning it seems to surge when she's in parking lots but never like it did today. She said when it happened and it finally slowed, all the dash lights on the bottom came on. Not sure if that was because it died or she panicked and shut it down or what. Just repeating what she tells me. The car has 150K on it roughly. Wiring is original. Is this a wiring problem, sensor, vac anyone have any ideas?