Corrigendum submitted by my PhD supervisor 1.5 years after I left? During my PhD studies, I published a journal article (1 of total 4) in a prestigious journal of my field. My PhD advisor wants to commercialize my PhD work and wanted me to help him without willing to credit me for my efforts. 
I found his emails harassing, malicious and blackmailing and have stopped responding him by directing his emails to spam folder. I have long left his lab after getting PhD and am currently working in industry. Suddenly, I received an email from the Journal that a corrigendum to my paper is submitted with me included as an author. 
I think there are some new experimental results that my advisor want to publish. Should I write to the journal and request to withdraw my authorship from the corrigendum?
I concur with the comment. This would be a highly unusual way to add new experimental results. Surely if the person was interested in applying or extending your work and had new experimental results they would publish on their own!

I would email them and ask what the contents of the changes are. Ethically, it's up to you if you think that you shouldn't be listed as an author on the corrigendum. There has been discussion about corrigendum authorship in the past, see here. The answer at that link agrees with what I've seen in practice: corrigendum authorship is identical to the original paper authorship even if not everyone worked on it.