Problems with proximity sensors, and voltages

Hello,
I wanted to use proximity sensors as endstops, but the signal out was 12v.
I didn't have any suitable resistors, but I had some 100k pots.

Bare in mind, I'm not at all strong with electronics, I though I'd make a small board to keep it tidy.
I connect the sensors to the pins show as blue/white/red.


Before I connected to the RAMPS, I dialed down the pots to about 3.5v.
However as soon as I connect it to the RAMP power, the x,y,z output is about 6v.

Is the circuit fundamentally wrong?

The sensor signal should be connected to the orange potmeter pin and the output to ramps is the blue potmeter pin.

Thank you. That's a bit embarrassing, but at least it's the sort of embarrassment I can learn from.