Better way to check if Object is of some Type bevor using it as said Type?

I have a huge if else statement where an Object is getting check for a specific type bevor it is used in a method. Is there a shorter/more effective way of doing this?

A bit simplified my code looks like this:

if(object is class1) someMethod(object as class1);
else if (object is class2) someMethod(object as class2);
else if (object is class3) someMethod(object as class3);
else if (object is class4) someMethod(object as class4);
else if (object is class5) someMethod(object as class5);
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