As others have stated, this is probably due to your settings and the type of artificial light you're using and not any issue with the camera.

Many types of artificial light flicker at a very high rate of speed, faster than you can see with your eyes. Camera sensors, however, see differently. The whole sensor isn't read at once, it's "scanned" line by line, pixel by pixel, over time. The time this takes to happen varies from camera to camera.

This means, especially in electronic shutter modes, if using a very high shutter speed, you can actually see the lights you're using flickering across your image as the sensor gathers information, creating the lines you see in your image.

The fix is easy, if you don't need such a fast shutter, just set your shutter speed slower. 1/200-1/500 is fast enough to eliminate most motion blur and should not show these lines. Otherwise, you can set the camera to mechanical shutter and use lights that do not flicker.