Intermittent brake lights

Good morning.
.
It sounds like your stop light switch is failing. I attached a picture and the procedure for replacing it. You can get the switch at any parts store.

Roy

Removal procedure:

Caution: Before removing or installing any electrical unit or when a tool or equipment could easily come in contact with "live" exposed electrical terminals, disconnect the negative battery cable to help prevent personal injury and/or damage to the vehicle or components. Unless instructed otherwise, the ignition switch must be in the "off" or "lock" position.

1. Disconnect the negative battery cable.
2. Disable the SIR.
3. Remove the pushrod retainer from the brake pedal pin. Use snap ring pliers.
4. Unsnap the stoplamp switch from the pushrod.
5. Disconnect the electrical connector from the stoplamp switch.