Could you please advise if I can install a combo switch+outlet to replace a single light switch in my kitchen although I have no ground wire in the box?
You did not indicate that this is the only circuit in that box. So I am going to tell you how, on the assumption that it is.
It is really simple. There is a tab that connects both screws on the line side of the device. Leave that in place. If you do not have a tab, you split that line and connect it to the line on the switch and the line on the outlet. Do the same thing with the neutral from that same circuit. You cannot share a neutral from another circuit. The load from the switch still goes to the load device. Do not use the back stab holes, always wrap the wire around the screws. Tape fully around the device once everything is connected. Push it all back into the box and secure the device to the box, replace the cover.
I would rather add a box on to the one that is in the wall, so that I would have two full boxes. One for a switch and one for an outlet. But that is personal preference.
Handy Andy In Mt Airy NC
It depens on how what wires are in the switch box. If the is only two wires on the switch and not other wires other than ground, you can not install a combo switch/outlet without doing some rewiring. If the power gose to the switch box then to the light, you would have two cables in the box in which case you can do as handyandy discribed. Tell us what is in the switch box.