Voltage handling is dictated by the isolation over the wire, not the wire gauge or wire type.
Current carrying capacity is where wire gauge comes into play, but even in a power section, you're max looking at like 500 ma, which is not alot of current.
Use whatever kind of wire you like, but make sure the gauge and isolation voltage rating are sufficient for what you're doing.
I use 22 gauge stranded teflon wire for my amp builds (minus the heaters, I like 14g solid for that). I like it because it's flexible and easy to work with. Other people like solid wire because it stays where you put it. In my experience though, I've had more failures from solid wire either breaking loose from the solder or straight up breaking than stranded. Plus solid wire is a pain to work with, IMO.
American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies