The way I read the text in the MM, there is no miss chance involved. Nowhere does it refer to a miss chance or your attacks missing or even concealment. Here is the relevant text:
"It can be harmed only by other incorporeal creatures, magic weapons or creatures that strike as magic weapons, and spells, spell-like abilities, or supernatural abilities. It is immune to all nonmagical attack forms. Even when hit by spells or magic weapons, it has a 50% chance to ignore any damage from a corporeal source (except for positive energy, negative energy, force effects such as magic missle, or attacks made with ghost touch weapons)."
The way I read that, you can hit an incorporeal creature with any kind of weapon (including a touch attack) as long as you beat its AC, but it is immune to the affects of nonmagical attack forms, in the same way that a swarm is immune to weapon damage (but not to being hit with weapons). Magic weapons hit just like anything else, and if you hit an incorporial creature with them, the attack has a 50% chance of having no affect.
So the way I read this, yes, you can affect an incorpoeal undead creature with both lay on hands and cure light wounds, and there is no "miss chance" involved.