Rear Break Lights (PLEASE HELP)

I just discovered that my brake lights in rear do not work, when opened bottom cover for brake pedal, look at the brake light switch, it was not connected, it is possible for the switch connector to slip of the connection, plus there is no free connection plug that I could use to plug in to this switch, or the light is switched on and off using the vacuum valve that is located above brake switch, this one is connected.

Car Specs:
1996 VW Passat GLX VR6-Manual

The only time I go to the service is to change oil, other than that I fix this car by my self.
I did some major repairs such as replacing heating element under the dash almost a year ago, it would cause my attention if I did not have brake lights since than, I started to thing that I did not connected this switch at the time of repair

The vacuum switch is for the cruise control. The electrical part should be connected. It has black/red & red/yellow wires.

The vacuum switch is for the cruise control. The electrical part should be connected. It has black/red & red/yellow wires.
Thank you so much.

Thank you so much.
I guess I did not connect it back last year, when I was replacing the heating core.
Now I have to find it that connector 