Transformer Going Up In Voltage Over Time

I have a transformer from a 1953 jukebox that seems to be increasing in voltage over time. When I first got it, it was outputting 32V. A week later it seemed steady at 38V, then 45V. Now I just measured it and it’s at 50V.

I see no visible signs of burning or excessive heat and I’ve not seen or smelled any smoke.

It is supposed to be a 115V => 32V (approx) transformer.

What is going on? Do I need to throw this thing out?