When you use a wand, you are NOT using a "spell" as it were, you are using an arcane device. There are rules about spell failure and such for SCROLLS, but those allow the casting of a spell - and wands aren't spells.
3.5 DMG, page 213, left side of page, entitled: "Spell Trigger" is a good place to start.
3.5 DMG, page 245, Right side of page, entitled: "Wands" is a good place to finish.
According to these two locations, the spells inside are ALMOST completed - all you need to do is trigger it - and ANYONE that casts that style of magic can activate it.
If a DM was silly enough to hand one out, a first level wizard could use a Wand of Wishes without a problem (except from local thieves!!).