There should be a hole somewhere in the can intended for filling/dispensing. Use that. ;-)
I treat gas cans like a hollow body guitar, I cut a hole for a control plate in a corner or on the side where the graphics are usually sparse. This allows you full access & eliminates trying to blindly snake stuff through the can? I’ve seen people cut an access port in the back end of the can too? Good luck on the build, let us know how it comes out.
Hi, if you can imagine that this wooded body is a tin fuel can, then this is what I would try.
I put all my electrics, pots, and piezo pickups through the output jack plate cavity. If I needed a magnetic pickup I would feed it in through the neck mounting pocket.
Or a plate on the side as Brian suggests might be best. Easier to get a pickup inside.