Lighthouse Mouse is a 1955 Warner Brothers Merrie Melodies animated cartoon, written by Sid Marcus and directed by Robert McKimson, with voice characterizations provided by Mel Blanc.
[3] It is 11 o'clock at night at a lighthouse on a small island, and the clock's pendulum is intermittently deflecting the light from the beacon into a mouse-hole downstairs, keeping the resident mouse wide awake.
Consequently, a cargo carrier named Australia crashes into the rocks on the shore of the island, causing several wooden crates to spill overboard.
When he hears a snap, he pulls on the string and sees he has caught Hippety, whom he thinks is a giant mouse, which makes his jaw drop to the floor and then fall into pieces.
The mouse cuts the extension cord in two places with a pair of scissors, putting the lights out again, and the furious light-keeper stalks Sylvester with a Shillelagh (a traditional Irish club/walking-stick) threatening to "fix that good-fer-nothin' pussycat.".
Seeing this from higher up the stairs puts Sylvester in a panic and runs up the stairs and attempts to reconnect the cord by stretching it but to no avail; as the light-house keeper approaches the room, Sylvester improvises a temporary solution by using himself as a conductor between the cut parts of the cord and gets a massive electric jolt, which turns the lights back on ("Lights on!
It explodes, completely destroying the cord beyond any chance of repair, while Sylvester, burnt and singed, is still waving his hand and head in terror as he knows he's done for.
In the final scene, the light-keeper, Polly, Hippety, and the mouse are sleeping happily while Sylvester is serving as the beacon, hooked up to a battery with the light projecting through his eyes.