Is it a bad earth or something else

[oldrocker72]

Hi everyone this is my first post so not sure it's in the right place to post this,

Anyway i have recently bought a Vauxhall Vectra Breeze 1.9 TDCi estate and the blown light bulb symbol has popped up on the dashboard, so i have checked which one it said and it's the tail light on the nearside but when i went to change the bulb, the bulb in the light cluster wasn't blown though,

Then all of a sudden it started to work again and the symbol had gone from the dashboard, but yesterday it was showing as blown again but like before the bulb wasn't fine but it's still showing as blown and the nearside tail light bulb keeps going bright then dim then bright again,

In the tail light cluster that's not working properly the reverse light still comes on it's just the tail light that's temperamental and only seems to work when it feels like it, so i'm wondering if it's a faulty earth or corroded connection somewhere it can't be at the light cluster because i'v looked at that one and it's brand new and all the metal connectors are clean,

So i am open to any advice as to what the issue could be and is it something i can fix myself or is it a garage job.