On Thu, 23 Mar 2017 13:52:55 -0000 (UTC), Doug Miller
wrote:

Micky wrote in
:

I'm renting a room from a woman and the power is 220 Volts. More than
once she has scorched one pin of her room heater's plug. The last
guy who replaced it adviced her to only turn on one of the two heater
halves.

I replaced the plug too and pointed out that if the receptacle is
loose, that's a problem too. She showed me that her bedroom socket
barely grips the plug or not at all.

Worn out. Safety hazard. Replace it.

She hasn't asked me yet to replace the whole socket, and even if I
did... the apartment was wired for internet cable, so it must have
been remodeled not that long ago, and I'm guessintg the electric
sockets were replaced too (I can ask her.)

Why would you think that? There's absolutely NO reason to suppose that the cable internet
installer would replace line-voltage electrical outlets as well -- or is competent to.

So.... Is there a device one can put into a 220v. socket (receptacle)
that will expand and make a tight connection with a loose socket?

You've got to be kidding me. The receptacle is worn out and DANGEROUS. It needs to be
replaced NOW, before it starts a fire.
You forgot who asked the question??