As others have noted - several Wish-containing items are scattered through the standard AD&D modules. They could also be gotten out of certain creatures, and cast by powerful wizards. We saw a wish or three in just about every campaign we ran. We only ended up with one PC wizard of high enough level to cast it, though we had a few scrolls that got used...
Psion said:
But then, there wasn't a "safe zone" for wishes. All wishes were subject to perverse interpretations.
I am reasonably certain a great many DMs
wanted to give out wishes, for this very reason. By comparison, these days wishes are not any particular fun for the DM, so there's little incentive.
As an example - playing the original Castle Ravenloft, on our first attempt, Stradh handed our party's butts to us on a silver platter. Nearly a TPK, with only my wizard and the party's svirfneblin illusionist surviving. Two characters, with an 18 and 17 Int, respectively. We knew well the perverse nature of wishes, so we thought as carefully as we could - because our DM was known to not allow lots of legalistic riders and conditions - the request had to be simple and bulletproof.
"I wish all my adventuring compatriots were alive, well, and in <nearby village>!"
The DM thought for five minutes...
*Poof!* - the deep gnome disappears a good sign, as the wish would have to move him to the village. I quickly read my scroll of teleport to get to the village myself...
... and arrive to find a town fully of brawling, naked aventurers! 22 of them, as I recall. The wish had transported (and occasionally ressurected) every single character the wizard had ever worked with. Many of them had left or died because they didn't get along well - with each other, or with the wizard.
I had to haul out our campaign's "Rogue's Gallery" - the DM had done it this way because expected that it would be a pugilistic bloodbath of epic proportions, and he hoped to see several PVP kills. He didn't count on one thing - the wizard and gnome still had their equipment, and they cooperated well. Nobody died, but we spent
four sessions hashing out each other's respective bacon, getting everyone's equipment back, and so on.
We did, eventually, hand Stradh his own butt on a platter. But that's another story...