I found 2 hidden switches in Saradush just in that evil merchants(forgot his name, sorry) home in the basement. They were protected by traps, I disarmed them, clicked on both of them, but nothing happens.
Are there any more hidden switches in that room? And what are they doing after activated?

I wonder what is the purpose of a thief`s find traps and open locks ability ???

Anyway, have you *really* looked *everywhere* ? ... namely in rooms that is *guarded*, ... maybe by two thiefs right and left to the door ?

Are these switches like something you can *activate* by clicking and that round arrow/activate symbol appears, or just a trapped part of the wall, hilightable by tab? I'm not sure what you are referring to but like Ragusa said, investigate the passageways more closely...

In fact they show up marked in red, just like traps and they can be found by using detect traps. You have to walk around a bit for they are positioned in a way that you cannot find them all at once.

Here comes the interesting part - I have been looking for a third one (how many are there anyway?) without a result. The Find Traps ability was around 140 I guess. I stand there, walk around, go through that hidden rooms behind the walls, but nothing. I find two swithches (they are marked as traps) activate them, but nothing happens:(
However, does this have any connenction to the hidden room? Because I managed to free the captive boy without even looking at those switches.

So?

Ok I don't know what all this hoopla about switches is :p but there are two things of importance that I know about in Kiser's basement. One being the captive young man, the second being the starfall ore, a recipe item for Cespenar in upgrading the mace you get from the Machine of Lum the Mad. The starfall ore is in one of the highlightable areas along the wall (hit tab).

Side note: Kiser's basement = Ranger cabin in Umar Hills? Another example of similar makeup of the level (i.e. compare the two maps, very similar.)

I have found EVERYTHING in that room, the ore, the boy, everything. As I said I stayed there for at least half an hour, to find out what those switches do, but nothing. The boy can be freed and the ore can be found without using them. I found the switches right after I let the boy out.

IIRC, you can use the switches to skip part of that particular quest.

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When you first talk to the merchant, he tells you to leave and go kill a mage on the walls. If you go downstairs at that point, you just see the one room, with no doorway in the wall. If you find and disarm the switches then, I think the wall opens and you can free the boy. The merchant and his men then attack you. This allows you to skip a bit of the legwork in the quest.

I'm basing this on dim recolections of a walkthrough, not personal experience, so forgive me for any errors.

Thank you, this sounds logical enough for me.