I don't know about GE, but I have done a few internships with other companies and what I've heard is that most interns do not get drug tested.
Drug testing interns
The thing to remember is that hiring and training interns is a cost to the business. Even if it is less than hiring a full-term employee.
So employers will usually do things like drug tests before any of the training expenses etc come into play...
If you have already been selected and trained to do your internship, then I would be seriously surprised if GE decided to drug test you now!