Two wires means you have a hot and a switched hot. You don't have a neutral, which is required for the outlet. So you can't hook that up.
You'll need to run 3 line wire so you have a proper neutral.
Based on a comment to the original question, this is a rental unit. In many places, doing your own electrical work, while allowed if you own your own home, is not permitted if you rent your home. In addition, the landlord is typically also prohibited from doing any electrical work. Which means it requires a licensed electrician, which often means the landlord will not be interested in getting any electrical work done unless required for safety as the cost can be significant.
That being said, conceptually (or practically, if you were doing this in a home you own or if you hired an electrician to do the job):
There are, essentially, three code compliant ways that a switch can be installed:
- Power -> switch -> switched device
In this scenario, hot & neutral go to the switch box. Hot connects to the switch. Neutral passes through to the switched device. The other side of the switch has switched hot which goes to the switched device. In this scenario, you have hot & neutral in the box and can connect a switch/receptacle combination device. But you don't have this.
- Power -> switched device -> switch, with neutral in the switch box
This is the way new switch loops are supposed to be installed. With this scenario, neutral is provided in the switch box for use with smart switches, timers and other devices. New code (I believe 2011 NEC) requires this now in most switch boxes. But you don't have this.
- Power -> switched device -> switch, with only hot & switched hot in the switch box
This appears to be your situation, and until recently it was perfectly legal, and it is legal if you don't change anything (except, of course, you actually want to change something). You have hot, but you don't have neutral. The only way to install an always hot device here, or a smart switch or anything else that requires a neutral, is to run a new cable. The work involved to do this can vary considerably depending on how far you have to run the cable, whether you have conduit or not, the type of walls (in case you need to cut holes to run the cable) and other factors.