My company was dispatched to a working fire in a 1.5 story single family dwelling. On arrival heavy smoke was pouring from the second story windows on the B and D sides, however, the windows were still intact. The captain and one firefighter entered the house, immediately did a primary search of the 1st floor and reported it to be negative before following the attack team to the bedroom on the 2nd floor. I was assigned “outside” truck duties; ventilation, laddering, utilities and to establish an IRIT. I proceeded to do a quick 360 to see our best access for any necessary removals and to locate and shut off the gas. I determined that I was going to ladder and vent the 2nd floor window on the B side due to cars blocking access to the D side. I grabbed a 24 ft ladder from the truck and headed to my target. Using the foundation of the house as my anchor point, I began to walk the ladder up when I encountered resistance. I knew there was a tree nearby so I assumed I was catching a branch, so… I pushed harder. Nothing. I walked the ladder back down to the ground to reposition when I looked up and noticed I had just raised the ladder into overhead wires. Luckily for me it was just the cable line and not an energized power line. I know I learn something new at EVERY fire and I believe we ALL do. This was a much needed wake up call to look around and use your head. Tunnel vision is something we all go through and can only be overcome with training, experience and maybe even a few hard learned lessons.