Add ToggleLight class to trigger lights in radius

+ Followed UE4 tutoial on mixing C++ and Blueprints
+ https://docs.unrealengine.com/4.27/en-US/ProgrammingAndScripting/ClassCreation/CodeAndBlueprints/
+ Added an in-editor and blueprint field ToggleLight::Radius to adjust
  trigger radius
+ Made stairs light up as you walk up them

Source/ThirdPerson/Public/ToggleLight.h

@@ -0,0 +1,53 @@
+// All content (c) Shaun Reed 2021, all rights reserved
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "GameFramework/Actor.h"
+#include "ToggleLight.generated.h"
+
+UCLASS()
+class THIRDPERSON_API AToggleLight : public AActor
+{
+  GENERATED_BODY()
+
+public:
+  // Sets default values for this actor's properties
+  AToggleLight();
+
+  UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "Switch Components")
+    class UPointLightComponent* PointLight1;
+
+  UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "Switch Components")
+    class USphereComponent* Sphere1;
+
+  // Radius of the trigger to toggle the light
+  UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Switch Variables")
+    float Radius = 50.0f;
+
+  /** the desired intensity for the light */
+  UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Switch Variables")
+    float DesiredIntensity;
+
+  /** Toggles the light component's visibility*/
+  UFUNCTION()
+    void ToggleLight();
+  
+  //
+  // Trigger functions
+
+  /** called when something enters the sphere component */
+  UFUNCTION(BlueprintNativeEvent, Category = "Switch Functions")
+    void OnOverlapBegin(class UPrimitiveComponent* OverlappedComp, class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);
+  void OnOverlapBegin_Implementation(class UPrimitiveComponent* OverlappedComp, class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);
+
+  /** called when something leaves the sphere component */
+  UFUNCTION(BlueprintNativeEvent, Category = "Switch Functions")
+    void OnOverlapEnd(class UPrimitiveComponent* OverlappedComp, class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);
+  void OnOverlapEnd_Implementation(class UPrimitiveComponent* OverlappedComp, class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);
+
+  //
+  // Update functions
+
+  virtual void Tick(float DeltaTime) override;
+};