tonearm feedback

I have been having an intermittent problem with what I will call feedback in my turntable system. Basically, I can hear a sound sometimes when I touch the tonearm to move it into place, or lift at the end of a record, only in the right channel. That channel also sometimes drops out during an album side, for a few seconds at a time, sometimes not at all, sometimes 5 or 6 times per side. Usually it comes back on its own, sometimes if I wiggle the tonearm wire a bit. So of course, I assume its the connection at the tonearm, so I changed out the tonearm wire for one that seems snug. Same problem, not as often but still there, right channel only.
First question. Why would a loose cable connection cause sound in one channel when I touch the arm. The sound is similar to that if you were cleaning a stylus with the sound on.
Second, if anyone thinks this is a grounding issue, would grounding the turntable separately from the tonearm wire ground help.
My system is an Oracle Delphi V SE with SME345 tonearm and Lyra Delos cartridge feeding a Manley Steelhead.
thanks