Object to create alpha transparent area on render

Is it possible to have an Object, that doesn’t create shadows and where the objects is the final render result should be alpha transparent?

like this?

addtional you can deactived the shadow ray visibility in the Object properties tab

Not exactly like this. I already tried this option, but I don’t want the shadow of the object.

As the answer explained, if you don’t want the shadow, turn it off. You can also set the Shadow dropdown to None in the Material settings for the object.

Didn’t see the last sentence… but sadly, it’s not working. I selected Holdout and deselected Shadow, but the object is still creating a shadow.
I’m trying to add an object into a picture of a hole in a wall. The bottom of the object is still covered by the wall on the ground, so I moddeled the part of the wall on the ground, that covers the bottom of the object. This part should create an alpha area on the render, so you can see the picture behind it. The light comes from the back, behind the object, so the object behind the hole should create a shadow on the floor in front of the wall. I added some lights in the back, but my wall part now creates a shadow on the ground as well. But this shadow is already in my original picture.

There are probably better solutions for this, but as a blender newbie, this was my first idea.

Here is my background:

Thank you for your help!