I went to City Electric Supply near me to buy lamps and some (if they even have) HID light fixtures, and electrical stuff, and the employee saiid that "You may have to be licensed in order to buy our products." Is this true that you need to be licensed in order to go into these electrical supply houses, like CES, Elliot Electrical supply, Graybar, and Grainger? Or do you not have to be licensed to go into these supply houses?

Please let me know down below.

I'm not licensed and nobody ever asked me when I went to suppliers. I might not get the contractor's pricing, but I always got what I asked for, no questions asked.

Yeah, I've been to multiple electrical/lighting supply stores and I've never been asked for a license. Now since I don't have an account with them, I'll have to pay the "cash" price instead of the price if I were to have a contractor's account.

I'm not licensed and nobody ever asked me when I went to suppliers. I might not get the contractor's pricing, but I always got what I asked for, no questions asked.

All you got to do is ask for the item and they'll give it to you?

Yes, but sometimes if it is even slightly unusual, I find it hard to explain what I want. They usually don't allow customers to peruse the aisles (they are behind the counter) so you have to ask for whatever you want. That and coupled with the fact that English is not my native language has resulted in a few times where I could not adequately explain what I wanted. I have, however, found a solution to the problem : I search up whatever I'm looking for online, print it out, and hand over the printed page at the counter and say "I want one like this." 95% of the time, it clears the confusion and I get what I want.

Yes, but sometimes if it is even slightly unusual, I find it hard to explain what I want. They usually don't allow customers to peruse the aisles (they are behind the counter) so you have to ask for whatever you want. That and coupled with the fact that English is not my native language has resulted in a few times where I could not adequately explain what I wanted. I have, however, found a solution to the problem : I search up whatever I'm looking for online, print it out, and hand over the printed page at the counter and say "I want one like this." 95% of the time, it clears the confusion and I get what I want.

I think that's the layout for the majority of these stores. The one I go to has common stuff like junction boxes, wirenuts, and common fittings in the front part of the store for self serve but most of the stuff you'll have to ask for at the counter. Knowing the exact item you're looking for will help. If they have a website I'll sometimes pull that up and show the person that. Sometimes you'll be surprised at what they have, I asked for a F4T5 striplight once, and to my surprise, they actually had a proper one in stock.

I think that's the layout for the majority of these stores. The one I go to has common stuff like junction boxes, wirenuts, and common fittings in the front part of the store for self serve but most of the stuff you'll have to ask for at the counter. Knowing the exact item you're looking for will help. If they have a website I'll sometimes pull that up and show the person that. Sometimes you'll be surprised at what they have, I asked for a F4T5 striplight once, and to my surprise, they actually had a proper one in stock.

I guess I'll try that, by showing the item that I want on their website.

Showing them on their own website is the best because they will have the item number right there.

The only problem I've ever had with a wholesaler is that some of them are reluctant to deal with the public. Not for any legal reasons, it's just that they're used to dealing with the trade and for everything to be done on account, I don't think some of them know what cash is 

Ordering online has never been a problem.

The only problem I've ever had with a wholesaler is that some of them are reluctant to deal with the public. Not for any legal reasons, it's just that they're used to dealing with the trade and for everything to be done on account, I don't think some of them know what cash is 

Ordering online has never been a problem.

Yeah, I'm not actually sure if the suppliers I've been to actually take cash but I meant "cash sales" as more of sales to the general public that don't have an account which is sometimes also called "counter sales" here. I've had no trouble paying via credit card or debit card at these places though. Most should be able to take some form of electronic payment. Of course like you mentioned, most of their business is done with the trades who will often have an account with the company instead.

There is yet another motivation to restrict access to just fewer selected individuals:
Prevent shoplifting of small, often expensive items, at the same time allow rather comfortable browsing and checking for the merchandise for the genuine customers.
Usually the access is restricted into the warehouse area, so those who do not meet the criteria need to rely on the counter only service.
The selection criteria then usually goes along something related to the merchandise, to distinguish who is more likely to be genuinely shopping and bring revenue vs who is more risky to become a shoplifter.
At least here it is often a possession of a business license in the trade, with smaller resale businesses the clerk often "tests" the customer by a few subtle question or assessing what his requests are, how much he knows about what he wants and when convinced he is really genuine customer with knowledge the trade needs, let him in even without that formal license. But bigger chains may have more formal, stricter policies.
Other aspects are goods safety: Someone who is just shopping for someone else and has no trade knowledge, may easily cause damage to some more delicate goods, even when unintentionally, yet it has less sense for such person to "dig through" the storage for anything.