my prev tenant complained that he has to change the bulbs, and pendaflour lighting freq (it keep burning up). And once measured it and it was above 240V.
He recommended for me to install some kind of regulator/stabilizer at inlet at the input supply to the house.

Anybody has any idea whether this is normal. Any idea what is the problem? Any other possible solution?
Is such devices exist? Where do i get it? and how much it cost?
My house if fairly new....5+ yrs old probably.

you can fix a voltage regulator but it will be expensive...
the problem is with TNB and there is nothing you can do about it...

240v is ok wat. Typically 190v~240v. Chk wiring lah, some wires short edi!
Replace mcb, veli cheap.

if complain to tnb...no use?
usually the main breaker shud trip if there is any overvoltage...i know of that for a fact...but never deal with tnb before...

not sure about wiring though...the problem happen to some of the people in the area...only recently....

what is the cost i will be looking at to install that regulator?

The breaker won't trip if over voltage. It trip when over amp.

You need to complain to tnb. The tnb need to look at their sub station. If no neutral return at their station, it can fried your electrical. Sometime it cause by the theft steal the busbar. It happen before at my friend house area.