I am going to answer my own question. It was really simple after all.

I renamed the folder "c:\[USER]\eTeks\Sweet Home 3D" to something else and then restarted the application.

It was then just a matter of installing the Plugin Manager and then locate the Wirings plugin, but this time I didn't import the pre-selected beta version, I chose an earlier non-beta one instead.

Sorry about creating a thread for this but perhaps someone will find it useful later.