What Krudds said on wattages. He's the man!
Now my spill...
As far as I am aware, I don't think the voltage makes a huge deal, just the amps rating. I've used straight 10 amp glass fuses on both 12v and 250v without issues.
That said, I wouldn't risk it though, just in case but check whether fuse should be fast or slow blow. Use a fast blow if unsure.
The difference being that fast blow fuses will blow on the slightest amp draw, whereas a slow blow will take short bursts of irregularties in amp draw but blow if applied to circuit for an extended period.
Fast blow fuses are generally a flat bimetal or single strand wire, Slow blows look more like a halogen globe wire (coiled) or ceramic coated.
My electronics 101 mainly relies on touch it with your fingers and see what happens (I was a fuse in my last life)