One problem related to brake warning switch has been reported for the 1998 Toyota Corolla. The most recently reported issues are listed below.
Making noises in front and brake warning light came on. Took it to the dealer, and said nothing was wrong. Had an oil change 12-oct-99, noticed that the brake pads were worn out. Also, replaced and surfaced rotors. Dealer said that consumer would need new brakes in about 12000 miles.