Review on Upgraded Central Pneumatic Air Compressor Pressure Switch Control Valve: Replacement Parts for 90-120 PSI, 240V Air Compressor by Omar Alradwan

They're very cheaply made but without the copper tubing and bending something custom made to fit a better made switch I should consider this one use. I think it's set at around 110psi, but it's easy to raise with a screw under the case. There are no holes for ground screws so I just unscrewed the nuts that are already there and attached them. I don't know if this provides sufficient ground, but it's just for the record as I have a very old power supply and need to rewire my whole house anyway. The 1/4 holes aren't very brittle, so use a little more thread seal tape than you think and screw it in until it stops leaking, and don't keep touching it. If you do need to replace the sensor or whatever is screwed in there I would also plan on buying a new switch as it will likely pop the second time you put it in. It works out. And it's only $10, so I can live with that.