First, sorry that I do not know what is the correct word to use instead of membership.
What I mean by that word, is I joined the site and I could easily access my profile on that site by switching from my account on other sites(in the Stack network).
In addition to my current Stack network's sites' membership, I think I also joined the Electrical Engineering site, some time ago and I do not want to create a new account in such case.
This can simply be my own mistake due to failure to remembering!
Also, in term of warnings and being banned from that account, I have checked my emails and there were none. I use the same email account for all of my account.