Overhead power service lines carry enough energy to power your home. That’s why they need to be respected and safety clearances followed. What you see in the photo is clearly a safety hazard. The weight of the tree limb is pushing down on the service wire. The breeze easily moves the limb and the wire rubs against it. On windy and wintery days it will push down on the wire even more. The end result will be a situation where shock or electrocutions are good possibilities.
The tree appears to have been in contact with the service wire for some time. The danger here is that the protective coating may be in a position of being rubbed off. Trees can be conductive. That means that they can carry an electrical current. So there is a distinct chance that the tree can become energized and injury could result from touching the tree.
If the weight of the limb doesn’t take down the service line then a storm might just do it. Another concern is children playing in the tree.
In this situation the closest disconnect for the service line is at the power company’s pole. There is no way for the homeowner to disconnect the power. Pruning this tree might result in inadvertent contact with electricity.
Pruning trees tangled in power lines is dangerous. Let the professionals that have specialised training and the proper insulated tools risk their lives. If you’re not qualified you’re putting yourself at risk.