In article .com,
writes:
I have been in my 1930's semi for over a year and since moving in I
have noticed that on any lighting circuit in the house (on different
fuseways), the lights seem to momentarily either dim or flicker maybe
once or twice during the evening.

Could use some more information...

What sort of area do you live in (city centre, rural, etc).
Do you know how your electricity is delivered (e.g. 1/2 mile
of poles coming over the hill?)
Do neighbours have same issue?
Can you associate the dimming with any other appliance you
have, such as a heater cycling on and off?
If you do switch on a large load (2kW heater, electric kettle,
electric shower, immersion heater, etc), does the same thing
happen?

Filamant lamps do amplify the effect of voltage variations as
larger changes in light output. Switching to energy saving compact
fluorescents would likely stop you from noticing the issue.

--
Andrew Gabriel