If you aren't totally confident working on it yourself, of course hire an electrician.
If it goes to the microwave it very well may be a dedicated circuit.
Flip the breaker when working on it of course.
Cut the stripped ends off and definitely use wire nuts to cap off the wires and cover the box with a blank plate if you are going to be leaving the wires in the box.
If it is a dedicated circuit you can also disconnect it in your electrical box, or have an electrician do it if you're not comfortable doing it yourself.
When you have the breaker flipped to it, does anything else not work? (outlets, lights, etc)
If it is on a circuit with other things, do what TOK said and disconnect it from the outlet it comes from and clip off the stripped ends and wire-nut there too.
If you know you will never want to hook this back up again, once it is disconnected at both ends (not live anymore) you can push the ends out of the electrical boxes and abandon them.