phone acting strange

I'm having my home windows replaced, and vinyl siding added. Not finished with the siding yet and its been over 2 weeks, yesterday my phone went dead, well the worker stapled and cut through two wires so I only had two phones and my dsl working. That was fixed temporarily, even though the wires were bare. Went to use my phone this morning after the worker got here, and I noticed a tone, not a hum but a tone. Strange. I talked to the worker and told him the trouble after I called repair service. The phone company tested the line remotely and said they could hear the tone also but the lines checked out ok. So the next step was to remove each jack plug and see if that changed. Nope on all 5 connectors. So I went to the main junction box on the outside and removed the jack to the home and inserted my phone into that jack. Clear as a bell. So In talking to the worker he noticed that where the bare wires were, they were touching His Metal Level. removed it and tone disappeared. Gave Him a couple of tiny wire nuts and used electrical tape and problem solved. Wonder why a metal level would introduce a tone? Hum I can understand (60 cycle) but a tone of about 200 Hz I don't know?