anyone know where oil pressure switch is on superb greeenline 1.6 TDI 2013. SC13AVY 

Try looking here https://m.youtube.com/watch?v=eon7Ha-Eak0

Is it because you don’t have the oil light indication when ignition is on ? 
I questioned this as I noticed I have no oil light but apparently that’s right according to people and watching YouTube seems to be correct. 
Seems to be strange 

Its because  oil light comes on intermittently  , oil and filter changed 3000 miles ago, so reckon its the switch  

oil level is ok 

is the golf same engine ?

Not sure to be honest, I just searched for CAYC oil pressure switch, thinking that was likely to be your engine code.

That video came up.

 

Have you looked there and failed to spot it?

Here, isn't it? Often the only sensor on an engine with a single wire going to it.

Find it yet?