Signature option in Edit Profile??

Do I have to delete my profile for it not to show in my postings automatically?

I looked all around Edit Profile and could not find an option to turn it off.

Since life is always complicated... There are different widgets on the screen depending on which browser you use. If you use one of the Microsoft browsers (Internet Explorer, Edge) then Tud's explanation is sufficient. On the other hand, if you use Firefox you will see a "Post Quick Reply" text box under the "+New Topic" and "+Reply" buttons.
The "Include Signature" box only appears when you reply using the "+Reply" button. If you simply type a response into the "Post Quick Reply" area (as I am doing now) your signature seems to always appear if you have one defined.
So, if you don't want your signature to appear and if you are a Firefox user then you have to be sure to press "+Reply" to bring up the "Include Signature" check box.
Oh, and like the man said, it is usually better to allow your signature to show, at least in on-topic threads. The information in your signature helps other members remember who you are and which topics you know about from personal experience. It also helps avoid getting advice that doesn't apply to your situation.

I like the bright blue text. I have noticed when going through the archives it was a common practice for members to have their signatures written in bright blue text. Apparently it fell out of favor at some point.

I got the signature thing down after a few years but quoting a post still baffles me. not one to look a gift horse in the mouth but the software on this site sucks bigly.