Could this be a badly shielded bulb/led ?
I had a Capri where the oil indicator would come on at random times - and one day I noticed it was lighting up in sync with some roadside trees
I traced it to a crack in the instrument cowl/dash that allowed sunlight through and had nothing to do with oil.
You might just have a bulb/led out of position. I have no idea why it might be flashing though.