A radio announcer of a show I listen to said she let her birds roam freely. One bird slowly pecked at a lamp cord that was out-stretched (to reach an outlet behind the middle of the couch). The wires were eventually bared, touched and caused a house fire.
Um, the stretched lampcord probably was a problem all on its own, without birdly assistance. Mine are pretty cautious not to land anywhere within the reach of a cat... at least during the day. But now I don't let the remaining bird out unsupervised.