Running STP and high-current AC cables together
Do not install power cable next to communications cable.


This is against the electrical code in most countries. In Australia, our Wiring Rules (AS 3000) specifically require power and communications cables to be physically separated, either by barriers or by distance.
If the power cable is damaged, and shorts to the communications cable, then the communications cable will be energized to the power voltage (i.e. 110 VAC or 230 VAC.) Communications devices are not designed to handle this voltage and may become live, posing a personnel safety hazard to anyone who touches them (i.e. you may kill someone.)