To answer both questions: Yes. I am referring to the Royal Air Force practice of using what were called "night intruders", which were twin engined heavy fighters such as the De Havilland Mosquito, tasked with night time intrusion of enemy airspace to attack enemy night fighters. Britain cut its night fighting teeth early in the Battle of Britain and found itself woefully deficient in the practice, scoring little success using single engined fighters like Hawker Hurricanes or Bolton Paul Defiants. The reason for this performance was the difficulty in acquiring targets, as even night fighters vectored in with ground radar had to rely on spotting the enemy aircraft's exhaust flames. Mounting airborne intercept radars solved this problem, but added the new issue that the only aircraft which could accommodate both the radar and radar operator were slow, poor performance converted twin engined bomber aircraft.

The solution to this was better aircraft: The De Havilland Mosquito (of wooden construction) arrived in 1942 and immediately proved perfectly suited to the night fighter role over UK airspace. The Air Force quickly realized its performance would make it the perfect intruder aircraft for dueling enemy night fighters. At the time British bomber streams were suffering badly from German night fighter attack, and little success was had in the use of slower aircraft like the Douglas Havoc as night intruders. The Mosquito proved its worth immediately against German Ju-88 and Me-110 night fighters, especially when newer version were able to equip better airborne radar and possessed longer range allowing them to patrol the length of Germany, which seriously effected German dominance of their night skies and caused serious losses amongst the comparatively poorer-performing German aircraft, especially older aircraft like the Me-110.

British tactics initially did not use radar due to the risk of technology falling into German hands, but later this was reversed. Airborne intercept radars, combined with two devices known as "Serrate" and "Perfecto", which allowed night intruders to home in on German Lichtenstain airborne radar and IFF (Identification Friend or Foe) transmissions, while both ranging alone and also while loosely attached as escorts to bomber streams heading to targets.The RAF's specialist 100 group took this a step further, using jammers mounted in heavy bombers to bluff enemy air defenses while the groups Mosquitoes performed what were called "Flower" missions, which involved patrolling German fighter bases to intercept aircraft as they landed, and keeping them suppressed by dropping bombs. Another tactic was "Mahmoud" missions, were Mosquitoes forged ahead of the bomber stream to raid German night fighter assembly points and destroy their attempts to form up. Another tactic involved Mosquitoes pretending to be heavy bombers to spoof enemy night fighters into coming close.

Although night intruders could only do so much against the night fighter threat, their effect was very important, as they seriously eroded the effectiveness of German air defenses, through both a very favorable attrition rate and sapping German interceptors morale, in what came to be known as "Moskitoschreck" (mosquito terror). The Luftwaffe was never able to mount an effective reply to the Mosquito over Germany, and the damaging effect on morale was even said to lead to greater crew and plane losses due to crashes, as Luftwaffe aircraft rushed to land to avoid attack.

From mid-1943 RAF Beaufighter and Mosquito night fighters started flying bomber support operations codenamed FLOWER and MAHMOUD, attacking Luftwaffe night fighters around their bases and assembly points. In November 1943 Bomber Command formed No. 100 Group, a special duties group including squadrons flying bombers with electronic countermeasures equipment in addition to the night fighter squadrons that operated over Europe.

The fighter squadrons of No. 100 Group, entirely equipped with Mosquitos by 1944, used a variety of devices to find German night fighters. SERRATE was a homing device that detected the airborne radar used by German night fighters (FuG 202/212 to start, later FuG 220), and PERFECTOS triggered German IFF transponders. Bomber Command had equipped its heavy bombers with MONICA, a tail warning radar to alert them when an enemy fighter was behind them, but the Germans rapidly developed a detector so MONICA actually guided German night fighters to their targets; No. 100 Group exploited this by equipping Mosquitos with MONICA that would then pose as a Lancaster, exploiting the superior manoeuvrability of the Mosquito to turn the tables on an attacker. The Mosquitos also had their own radar, AI Mk IV at first, later AI Mk VIII and X centimetric radar, once authorised to use it over enemy territory.

The fighter units of No. 100 Group flew 8,000 offensive sorties and claimed 258 enemy aircraft destroyed for 69 losses.

Figures from Night Fighters: A Development and Combat History, Bill Gunston, and 100 Group - Fighter Operations, Martin Streetly, from the RAF Historical Society Journal No. 28.