How do I help this squirrel?

[jansharp]

This squirrel lives in my yard and has a growth under his/her neck that keeps getting bigger and bigger. I've seen it develop over a month now and I'm pretty convinced it's not warbles/bot flys because it seems smooth without any holes. The growth has a darkish/bloodish tint but I'm able to observe it from about 10 metres away so can't say for sure. The squirrel seems not to be too bothered by it -- it's playing and eating but the growth is obviously getting in the way of its mobility.

Not sure how to proceed but want to help. Link to correctly oriented picture is also here (https://imgur.com/a/TjwOgC0)

322295

[stepnstone]

My opinion it's an obvious abscess that continues to fill, I'm somewhat surprised with it's size it hasn't burst on it's own as many do.
Unless one has the capabilities themselves...
Live trap, get to a rehabilatator who can lance, drain, medicate, and then release back in it's home area.