If one of the two metal things on a electrical cord is larger than the other, but the holes in the outlet are the same size so it won't fit, is it okay to force it in?
If the openings in the outlet are actually the same size, this is a very very old outlet. it probably has no ground, ie, it has two connections, not three. But double check it carefully, the difference is small. You can buy an adaptor (see link). But be very careful you orient it correctly. And you should get your house rewired before you have an electrical fire. .
The holes on the outlet are never the same as dictated by code. You may not be able to detect the difference but they are different. The purpose for the blades to be the same size is to ensure that your connection is properly polarized.
The larger size metal pin, is larger because it denotes the positive terminal, and the smaller one denotes the negative terminal. Usually in most wall outlets, the positive terminal would be on the left side and the negative would be on the right. So if you're going to force it in (because the plate of the outlet is wrong or something) then force the bigger metal pin on the left and the smaller metal pin on the right of the outlet.
the holes in the outlet are not the same size, they are slightly different also
If the holes in he receptacle are the same size, there are two possible reasons. 1. This is a very old receptacle, which I doubt. 2. This is a receptacle polarized for another voltage. The different configurations of the receptacles and plugs are by design, to keep people from connecting electrical devices to the wrong voltage supply. There is equipment with plugs having the same receptacle blade width, but this equipment is double insulated and code does not require the plugs for this equipment to be polarized. TexMav.
