Oil pressure light

Hi ,
Seeking a bit of guidance before I get stuck next weekend , strange initial link , but basically the oil pressure light started coming on when ever touched the trip switch in the top centre of the dash , thought that's weird but did nothing about it , then a week or so later the light started to flicker whilst on the move , a sharp tap on the gauge , and it went out . Now however it's staying on constantly . Assume it's an electrical gremin in the dash , so plan to have a look . Any thoughts on what I should be looking for would be appreciated .
Cheers
Steve

Short behind the clocks (wire from lamp, white with brown tracer, touching earth somewhere), faulty switch or low oil pressure.

Possibly slack bulb for low oil pressure , take lead off sender and earth it light should come on and stay on.
Check oil level and replace sender ASAP.

Thanks for the feedback . Steve