m4 macbook air giving a static charge

That is usually due to an issue with the home electrical wiring. You can try using a grounded AC Cord (aka Power Extension Cable)....here is an Apple link to the US version (other regions may have one as well):

Power Adapter Extension Cable - Apple

You probably should have an electrician check out your home's electrical wiring.

Of course Apple will want you to take the laptop to an Apple Store to be checked out. It won't surprise me if you see such a post from a forum moderator soon.

If it's within warranty and/or you have Applecare, contact Official Apple Support

A big +1 on HWTech's info. You can't imagine how wonky house wiring can be, even where it is "supposed" to be subject to municipal inspection at time of installation. Many older buildings are "grandfathered."

The extension cable effectively provides a ground by making contact with the metal rivet that secures it to the charger. Inside the "duck-head" of the extension you can see the grounding contact: