They left a message saying I may be in PGE's CARE program and that they recently sent me some information.  I don't know if this number is actually PGE.  If I have a question about my CARE status, or if I stop getting the discount I'll just ask about it at the office where I can be certain that I'm dealing with PGE and not a phisher.

This number is part of PG&E's CARE program and I got the same message as Steve above although it has you call back to 1-888-538-5960. They want to work with either a homeowner or landlord to qualify them for up to two years of CARE assistance by taking offering weather stripping, etc. I explained that I am in an apartment and not allowed to make changes without prior authorization from the landlord. They thanked me and hung up.