Hello bowlesj,
You may just have a hot spot on one of your switch connection/s.
A hot spot is caused by a wire or wires that have not been screwed down in the contact
housing properly, but its still making some contact.
What happened's over time is that you get slight miniature arching that you can't usually
hear.
The arching causes heat and carbonization on the wire conductor and the switch housing.
It gets worse as time goes by. In effect its creating a resistor between the two conductors
with the value increasing over time.
Due to this resistance, the arching then looks for an easier way to close the circuit. Hence
it starts arching further down the wire and the upper part of the switch housing.
When all that gets carbonized, it starts looking for a different path. i.e. your fingers.
This type of arching CAN play havoc with other lights in the house, causing flicker, as
this arching is creating induced noise in the lighting mains, especially if it can reach
from the wire to your fingers.
Either way, if its all being caused by any of the suggestions above or my explanation,
the switch really needs to be replaced.
I'm quite surprised it lasted the 37 years and didn't fall apart sooner.
You also need to ensure that none of the wires have any carbonization on them. If so,
cut them a tad shorter and expose fresh wire.
You can purchase a non-contact AC voltage detector to determine if a light switch or
power point is live. Check the link below:
Detector
If you do decide to replace the switch yourself, then as Brian has already suggested, turn off
the whole house power at the fuse box. You can use the detector to ensure that no voltage
is present at the switch.
I'm not sure which country you're from and whether or not you're allowed to do your own house
wiring, but if you live in Australia, then it would be illegal for you to do it yourself.
It MUST be done by a licensed electrician.
Yet, you are allowed to wire up your own house, provided you get an electrician to come and see
what you've done, and if he approves of the work, then he's the only one that can connect it to
live wiring, then he will certify the work.
Strange thing is, there have been more fatalities of people being electrocuted when doing a DYI
on their house, than people who live in New Zealand to which they ARE allowed to do their own
wiring. :?::?::?:
At one stage, the Electrical Union here in Oz, wanted to stop appliance technicians from replacing
mains power cords on equipment. Due to it being a mains wiring, they needed to certify it. Which
is complete bullshit. It was just another way to try and get more business for the sparkies. :x
Thankfully it never got passed. :clap:
Regards,
Relayer