I have a Hitachi trk 8270w that is doing some strange things. When the selector switch is turned to radio it hums in and out of radio at low volume. It sometimes even makes a weird humming noise. When I turn the selector switch to tape and press play the RADIO comes on perfectly...??? Has anyone ever experienced anything like this?

First thing to try is using an electrical contact cleaner fluid to clean selector switch. A hum is a good indication of a leaky electrolytic capacitor in the tuner not filtering out DC current properly but when cassette circuit is engaged (assuming shorted, dirty, ect. selector switch), it's perhaps providing enough stray capacitance to quiet the tuner. This is just a theory, I can't tell you for certain but it might put you on the right track to solving your puzzle.

with Czrem. I had the same problem with my Hitachi,I cleaned the power switch and no more humming or other problems.

I will try to clean the switch and see if that helps. Thanks