Is Aluminum electrical wiring safe?

The short answer is yes, with proper connections, and wire sizing, aluminum wiring is fine. Surprising to many, most main service conductors (from pole to house) are made with aluminum wiring.

The problems with aluminum wiring arise when undersized, or incorrectly connected to copper wiring and/or unapproved switches, receptacles, etc. In those cases, the dissimilar metals can react with one another, creating a possible fire hazard.