protect

Sorry if this seems a silly question, but how does one secure/protect a pre-amp circuitboard inside a body cavity? I’ve only ever build passive instruments, but my recent build uses a Stinger 77 active pre amp. Will it create grounding issues and stop it working if the circuitboard touch...

I applied a decal to my 5 string Ibanez GSRM25 Mikro bass, among other visual mods, and I am wondering if I ought to cover it with a protecting layer of clear varnish, or you think it would be fine to just leave it as it is without increasing the risk of it cracking, rubbing or wearing off...