socket, wall socket/plug, power socket, power-point 
[noun]
[het stop-con-tact, de stop-con-tac-ten]
"Stopcontacten" are everywhere in the Netherlands 
Sometimes you may hear the somewhat more formal term "wandcontactdoos" or "contactdoos".
Dutch power sockets have two holes, and sometime a ground pin. For the nerds among us: the official socket standard(s) used in the Netherlands is Type C and Type F and Type E/F…
Examples:
- "Kinderen, probeer nooit een pen in een stopcontact te steken…" – "Doe niet zo betuttelend…"
("Children, never try to stick a pen into a power socket…" – "Don’t be patronizing like that…")
- "Steek eerst de stekker in het stopcontact, zet dan de computer aan."
("First put the plug in the power socket, then turn on the computer.")
- "Als je de gloeilamp gaat vervangen, trek dan eerst de stekker uit het stopcontact."
("If you’re going to change the light bulb, first pull the plug from the socket.")
Expressions:
- "Balen als een stekker": to be really fed up with something.
- "Zijn/haar stoppen sloegen door": He/she went berserk, lit.: He/She blew his/her fuses.
Example:
- "Toen Frank hoorde dat hij ontslagen zou worden, sloegen bij hem de stoppen door."
("When Frank heard that he would be fired, he went berserk.")
Related words:
- Stop: plug, fuse [noun] [de stop, de stoppen].
- Stekker: plug [noun] [de stekker, de stekkers].
Example:
- "Of je stopt de stekker erin…"
("Or you could put the plug in…" See Extra)
- Doos: box [noun] [de doos, de dozen].
- Stekkerdoos: multiple socket
- Kortsluiting: short-circuit [noun] [de kortsluiting, de kortsluitingen].
- Elektriciteit: electricity [noun] [de elektriciteit, <no plural>].
- Stroom: current [noun] [de stroom, de stromen].
- Spanning: voltage [noun] [de spanning, de spanningen].
Extra:
Somewhere in the eighties, there was a commercial by IBM running on Dutch television, which became very popular. It became particularly popular because of the phrase "Of je stopt de stekker erin" … Check out the very, very out-dated clip on YouTube