Yes, there is another switch that operate on the same light.Your existing switch looks like a 3 way switch. Is there another switch somewhere that also operates the same light(s) ?
The new combo switch appears to be a single pole/receptacle combination.
Is would be the wrong switch for a 3way set up. You would need a 3way switch/receptacle combination.
Thanks both for your precious answers, Oso954 yes, i removed the wirenut only to take the picture, and to show it to you. I will let you know tomorrow when the new outlet will be at homeOne thing bugging me about the pic of the existing switch. The three white wires twisted together without a wire nut. Is that how you found it or did you remove the wire nut?
One of those 3wires appears to be an extremely short pigtail to the other white which is under the black wirenut.
I'd remove the short pigtail and combine the connections.
I agree with Jeff's instructions for the new device connections.